1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $ 65 * $DragonFly: src/sys/vm/vm_map.c,v 1.56 2007/04/29 18:25:41 dillon Exp $ 66 */ 67 68 /* 69 * Virtual memory mapping module. 70 */ 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/kernel.h> 75 #include <sys/proc.h> 76 #include <sys/lock.h> 77 #include <sys/vmmeter.h> 78 #include <sys/mman.h> 79 #include <sys/vnode.h> 80 #include <sys/resourcevar.h> 81 #include <sys/shm.h> 82 #include <sys/tree.h> 83 #include <sys/malloc.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_param.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_page.h> 90 #include <vm/vm_object.h> 91 #include <vm/vm_pager.h> 92 #include <vm/vm_kern.h> 93 #include <vm/vm_extern.h> 94 #include <vm/swap_pager.h> 95 #include <vm/vm_zone.h> 96 97 #include <sys/thread2.h> 98 #include <sys/sysref2.h> 99 100 /* 101 * Virtual memory maps provide for the mapping, protection, 102 * and sharing of virtual memory objects. In addition, 103 * this module provides for an efficient virtual copy of 104 * memory from one map to another. 105 * 106 * Synchronization is required prior to most operations. 107 * 108 * Maps consist of an ordered doubly-linked list of simple 109 * entries; a single hint is used to speed up lookups. 110 * 111 * Since portions of maps are specified by start/end addresses, 112 * which may not align with existing map entries, all 113 * routines merely "clip" entries to these start/end values. 114 * [That is, an entry is split into two, bordering at a 115 * start or end value.] Note that these clippings may not 116 * always be necessary (as the two resulting entries are then 117 * not changed); however, the clipping is done for convenience. 118 * 119 * As mentioned above, virtual copy operations are performed 120 * by copying VM object references from one map to 121 * another, and then marking both regions as copy-on-write. 122 */ 123 124 static void vmspace_terminate(struct vmspace *vm); 125 static void vmspace_dtor(void *obj, void *private); 126 127 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore"); 128 129 struct sysref_class vmspace_sysref_class = { 130 .name = "vmspace", 131 .mtype = M_VMSPACE, 132 .proto = SYSREF_PROTO_VMSPACE, 133 .offset = offsetof(struct vmspace, vm_sysref), 134 .objsize = sizeof(struct vmspace), 135 .mag_capacity = 32, 136 .flags = SRC_MANAGEDINIT, 137 .dtor = vmspace_dtor, 138 .ops = { 139 .terminate = (sysref_terminate_func_t)vmspace_terminate 140 } 141 }; 142 143 #define VMEPERCPU 2 144 145 static struct vm_zone mapentzone_store, mapzone_store; 146 static vm_zone_t mapentzone, mapzone; 147 static struct vm_object mapentobj, mapobj; 148 149 static struct vm_map_entry map_entry_init[MAX_MAPENT]; 150 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU]; 151 static struct vm_map map_init[MAX_KMAP]; 152 153 static void vm_map_entry_shadow(vm_map_entry_t entry); 154 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *); 155 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); 156 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 157 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); 158 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); 159 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); 160 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, 161 vm_map_entry_t); 162 static void vm_map_split (vm_map_entry_t); 163 static void vm_map_unclip_range (vm_map_t map, vm_map_entry_t start_entry, vm_offset_t start, vm_offset_t end, int *count, int flags); 164 165 /* 166 * vm_map_startup: 167 * 168 * Initialize the vm_map module. Must be called before 169 * any other vm_map routines. 170 * 171 * Map and entry structures are allocated from the general 172 * purpose memory pool with some exceptions: 173 * 174 * - The kernel map and kmem submap are allocated statically. 175 * - Kernel map entries are allocated out of a static pool. 176 * 177 * These restrictions are necessary since malloc() uses the 178 * maps and requires map entries. 179 */ 180 void 181 vm_map_startup(void) 182 { 183 mapzone = &mapzone_store; 184 zbootinit(mapzone, "MAP", sizeof (struct vm_map), 185 map_init, MAX_KMAP); 186 mapentzone = &mapentzone_store; 187 zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), 188 map_entry_init, MAX_MAPENT); 189 } 190 191 /* 192 * vm_init2 - called prior to any vmspace allocations 193 */ 194 void 195 vm_init2(void) 196 { 197 zinitna(mapentzone, &mapentobj, NULL, 0, 0, 198 ZONE_USE_RESERVE | ZONE_SPECIAL, 1); 199 zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1); 200 pmap_init2(); 201 vm_object_init2(); 202 } 203 204 205 /* 206 * Red black tree functions 207 */ 208 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); 209 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); 210 211 /* a->start is address, and the only field has to be initialized */ 212 static int 213 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) 214 { 215 if (a->start < b->start) 216 return(-1); 217 else if (a->start > b->start) 218 return(1); 219 return(0); 220 } 221 222 /* 223 * Allocate a vmspace structure, including a vm_map and pmap. 224 * Initialize numerous fields. While the initial allocation is zerod, 225 * subsequence reuse from the objcache leaves elements of the structure 226 * intact (particularly the pmap), so portions must be zerod. 227 * 228 * The structure is not considered activated until we call sysref_activate(). 229 */ 230 struct vmspace * 231 vmspace_alloc(vm_offset_t min, vm_offset_t max) 232 { 233 struct vmspace *vm; 234 235 vm = sysref_alloc(&vmspace_sysref_class); 236 bzero(&vm->vm_startcopy, 237 (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy); 238 vm_map_init(&vm->vm_map, min, max, NULL); 239 pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */ 240 vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ 241 vm->vm_shm = NULL; 242 vm->vm_exitingcnt = 0; 243 cpu_vmspace_alloc(vm); 244 sysref_activate(&vm->vm_sysref); 245 return (vm); 246 } 247 248 /* 249 * dtor function - Some elements of the pmap are retained in the 250 * free-cached vmspaces to improve performance. We have to clean them up 251 * here before returning the vmspace to the memory pool. 252 */ 253 static void 254 vmspace_dtor(void *obj, void *private) 255 { 256 struct vmspace *vm = obj; 257 258 pmap_puninit(vmspace_pmap(vm)); 259 } 260 261 /* 262 * Called in two cases: 263 * 264 * (1) When the last sysref is dropped, but exitingcnt might still be 265 * non-zero. 266 * 267 * (2) When there are no sysrefs (i.e. refcnt is negative) left and the 268 * exitingcnt becomes zero 269 * 270 * sysref will not scrap the object until we call sysref_put() once more 271 * after the last ref has been dropped. 272 */ 273 static void 274 vmspace_terminate(struct vmspace *vm) 275 { 276 int count; 277 278 /* 279 * If exitingcnt is non-zero we can't get rid of the entire vmspace 280 * yet, but we can scrap user memory. 281 */ 282 if (vm->vm_exitingcnt) { 283 shmexit(vm); 284 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, 285 VM_MAX_USER_ADDRESS); 286 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, 287 VM_MAX_USER_ADDRESS); 288 289 return; 290 } 291 cpu_vmspace_free(vm); 292 293 /* 294 * Make sure any SysV shm is freed, it might not have in 295 * exit1() 296 */ 297 shmexit(vm); 298 299 KKASSERT(vm->vm_upcalls == NULL); 300 301 /* 302 * Lock the map, to wait out all other references to it. 303 * Delete all of the mappings and pages they hold, then call 304 * the pmap module to reclaim anything left. 305 */ 306 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 307 vm_map_lock(&vm->vm_map); 308 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, 309 vm->vm_map.max_offset, &count); 310 vm_map_unlock(&vm->vm_map); 311 vm_map_entry_release(count); 312 313 pmap_release(vmspace_pmap(vm)); 314 sysref_put(&vm->vm_sysref); 315 } 316 317 /* 318 * This is called in the wait*() handling code. The vmspace can be terminated 319 * after the last wait is finished using it. 320 */ 321 void 322 vmspace_exitfree(struct proc *p) 323 { 324 struct vmspace *vm; 325 326 vm = p->p_vmspace; 327 p->p_vmspace = NULL; 328 329 if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref)) 330 vmspace_terminate(vm); 331 } 332 333 /* 334 * vmspace_swap_count() 335 * 336 * Swap useage is determined by taking the proportional swap used by 337 * VM objects backing the VM map. To make up for fractional losses, 338 * if the VM object has any swap use at all the associated map entries 339 * count for at least 1 swap page. 340 */ 341 int 342 vmspace_swap_count(struct vmspace *vmspace) 343 { 344 vm_map_t map = &vmspace->vm_map; 345 vm_map_entry_t cur; 346 vm_object_t object; 347 int count = 0; 348 int n; 349 350 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 351 switch(cur->maptype) { 352 case VM_MAPTYPE_NORMAL: 353 case VM_MAPTYPE_VPAGETABLE: 354 if ((object = cur->object.vm_object) == NULL) 355 break; 356 if (object->type != OBJT_SWAP) 357 break; 358 n = (cur->end - cur->start) / PAGE_SIZE; 359 if (object->un_pager.swp.swp_bcount) { 360 count += object->un_pager.swp.swp_bcount * 361 SWAP_META_PAGES * n / object->size + 1; 362 } 363 break; 364 default: 365 break; 366 } 367 } 368 return(count); 369 } 370 371 /* 372 * vmspace_anonymous_count() 373 * 374 * Calculate the approximate number of anonymous pages in use by 375 * this vmspace. To make up for fractional losses, we count each 376 * VM object as having at least 1 anonymous page. 377 */ 378 int 379 vmspace_anonymous_count(struct vmspace *vmspace) 380 { 381 vm_map_t map = &vmspace->vm_map; 382 vm_map_entry_t cur; 383 vm_object_t object; 384 int count = 0; 385 386 for (cur = map->header.next; cur != &map->header; cur = cur->next) { 387 switch(cur->maptype) { 388 case VM_MAPTYPE_NORMAL: 389 case VM_MAPTYPE_VPAGETABLE: 390 if ((object = cur->object.vm_object) == NULL) 391 break; 392 if (object->type != OBJT_DEFAULT && 393 object->type != OBJT_SWAP) { 394 break; 395 } 396 count += object->resident_page_count; 397 break; 398 default: 399 break; 400 } 401 } 402 return(count); 403 } 404 405 406 407 408 /* 409 * vm_map_create: 410 * 411 * Creates and returns a new empty VM map with 412 * the given physical map structure, and having 413 * the given lower and upper address bounds. 414 */ 415 vm_map_t 416 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max) 417 { 418 if (result == NULL) 419 result = zalloc(mapzone); 420 vm_map_init(result, min, max, pmap); 421 return (result); 422 } 423 424 /* 425 * Initialize an existing vm_map structure 426 * such as that in the vmspace structure. 427 * The pmap is set elsewhere. 428 */ 429 void 430 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap) 431 { 432 map->header.next = map->header.prev = &map->header; 433 RB_INIT(&map->rb_root); 434 map->nentries = 0; 435 map->size = 0; 436 map->system_map = 0; 437 map->infork = 0; 438 map->min_offset = min; 439 map->max_offset = max; 440 map->pmap = pmap; 441 map->first_free = &map->header; 442 map->hint = &map->header; 443 map->timestamp = 0; 444 lockinit(&map->lock, "thrd_sleep", 0, 0); 445 } 446 447 /* 448 * Shadow the vm_map_entry's object. This typically needs to be done when 449 * a write fault is taken on an entry which had previously been cloned by 450 * fork(). The shared object (which might be NULL) must become private so 451 * we add a shadow layer above it. 452 * 453 * Object allocation for anonymous mappings is defered as long as possible. 454 * When creating a shadow, however, the underlying object must be instantiated 455 * so it can be shared. 456 * 457 * If the map segment is governed by a virtual page table then it is 458 * possible to address offsets beyond the mapped area. Just allocate 459 * a maximally sized object for this case. 460 */ 461 static 462 void 463 vm_map_entry_shadow(vm_map_entry_t entry) 464 { 465 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 466 vm_object_shadow(&entry->object.vm_object, &entry->offset, 467 0x7FFFFFFF); /* XXX */ 468 } else { 469 vm_object_shadow(&entry->object.vm_object, &entry->offset, 470 atop(entry->end - entry->start)); 471 } 472 entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; 473 } 474 475 /* 476 * Allocate an object for a vm_map_entry. 477 * 478 * Object allocation for anonymous mappings is defered as long as possible. 479 * This function is called when we can defer no longer, generally when a map 480 * entry might be split or forked or takes a page fault. 481 * 482 * If the map segment is governed by a virtual page table then it is 483 * possible to address offsets beyond the mapped area. Just allocate 484 * a maximally sized object for this case. 485 */ 486 void 487 vm_map_entry_allocate_object(vm_map_entry_t entry) 488 { 489 vm_object_t obj; 490 491 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 492 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */ 493 } else { 494 obj = vm_object_allocate(OBJT_DEFAULT, 495 atop(entry->end - entry->start)); 496 } 497 entry->object.vm_object = obj; 498 entry->offset = 0; 499 } 500 501 /* 502 * vm_map_entry_reserve_cpu_init: 503 * 504 * Set an initial negative count so the first attempt to reserve 505 * space preloads a bunch of vm_map_entry's for this cpu. Also 506 * pre-allocate 2 vm_map_entries which will be needed by zalloc() to 507 * map a new page for vm_map_entry structures. SMP systems are 508 * particularly sensitive. 509 * 510 * This routine is called in early boot so we cannot just call 511 * vm_map_entry_reserve(). 512 * 513 * May be called for a gd other then mycpu, but may only be called 514 * during early boot. 515 */ 516 void 517 vm_map_entry_reserve_cpu_init(globaldata_t gd) 518 { 519 vm_map_entry_t entry; 520 int i; 521 522 gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2; 523 entry = &cpu_map_entry_init[gd->gd_cpuid][0]; 524 for (i = 0; i < VMEPERCPU; ++i, ++entry) { 525 entry->next = gd->gd_vme_base; 526 gd->gd_vme_base = entry; 527 } 528 } 529 530 /* 531 * vm_map_entry_reserve: 532 * 533 * Reserves vm_map_entry structures so code later on can manipulate 534 * map_entry structures within a locked map without blocking trying 535 * to allocate a new vm_map_entry. 536 */ 537 int 538 vm_map_entry_reserve(int count) 539 { 540 struct globaldata *gd = mycpu; 541 vm_map_entry_t entry; 542 543 crit_enter(); 544 545 /* 546 * Make sure we have enough structures in gd_vme_base to handle 547 * the reservation request. 548 */ 549 while (gd->gd_vme_avail < count) { 550 entry = zalloc(mapentzone); 551 entry->next = gd->gd_vme_base; 552 gd->gd_vme_base = entry; 553 ++gd->gd_vme_avail; 554 } 555 gd->gd_vme_avail -= count; 556 crit_exit(); 557 return(count); 558 } 559 560 /* 561 * vm_map_entry_release: 562 * 563 * Releases previously reserved vm_map_entry structures that were not 564 * used. If we have too much junk in our per-cpu cache clean some of 565 * it out. 566 */ 567 void 568 vm_map_entry_release(int count) 569 { 570 struct globaldata *gd = mycpu; 571 vm_map_entry_t entry; 572 573 crit_enter(); 574 gd->gd_vme_avail += count; 575 while (gd->gd_vme_avail > MAP_RESERVE_SLOP) { 576 entry = gd->gd_vme_base; 577 KKASSERT(entry != NULL); 578 gd->gd_vme_base = entry->next; 579 --gd->gd_vme_avail; 580 crit_exit(); 581 zfree(mapentzone, entry); 582 crit_enter(); 583 } 584 crit_exit(); 585 } 586 587 /* 588 * vm_map_entry_kreserve: 589 * 590 * Reserve map entry structures for use in kernel_map itself. These 591 * entries have *ALREADY* been reserved on a per-cpu basis when the map 592 * was inited. This function is used by zalloc() to avoid a recursion 593 * when zalloc() itself needs to allocate additional kernel memory. 594 * 595 * This function works like the normal reserve but does not load the 596 * vm_map_entry cache (because that would result in an infinite 597 * recursion). Note that gd_vme_avail may go negative. This is expected. 598 * 599 * Any caller of this function must be sure to renormalize after 600 * potentially eating entries to ensure that the reserve supply 601 * remains intact. 602 */ 603 int 604 vm_map_entry_kreserve(int count) 605 { 606 struct globaldata *gd = mycpu; 607 608 crit_enter(); 609 gd->gd_vme_avail -= count; 610 crit_exit(); 611 KASSERT(gd->gd_vme_base != NULL, ("no reserved entries left, gd_vme_avail = %d\n", gd->gd_vme_avail)); 612 return(count); 613 } 614 615 /* 616 * vm_map_entry_krelease: 617 * 618 * Release previously reserved map entries for kernel_map. We do not 619 * attempt to clean up like the normal release function as this would 620 * cause an unnecessary (but probably not fatal) deep procedure call. 621 */ 622 void 623 vm_map_entry_krelease(int count) 624 { 625 struct globaldata *gd = mycpu; 626 627 crit_enter(); 628 gd->gd_vme_avail += count; 629 crit_exit(); 630 } 631 632 /* 633 * vm_map_entry_create: [ internal use only ] 634 * 635 * Allocates a VM map entry for insertion. No entry fields are filled 636 * in. 637 * 638 * This routine may be called from an interrupt thread but not a FAST 639 * interrupt. This routine may recurse the map lock. 640 */ 641 static vm_map_entry_t 642 vm_map_entry_create(vm_map_t map, int *countp) 643 { 644 struct globaldata *gd = mycpu; 645 vm_map_entry_t entry; 646 647 KKASSERT(*countp > 0); 648 --*countp; 649 crit_enter(); 650 entry = gd->gd_vme_base; 651 KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); 652 gd->gd_vme_base = entry->next; 653 crit_exit(); 654 return(entry); 655 } 656 657 /* 658 * vm_map_entry_dispose: [ internal use only ] 659 * 660 * Dispose of a vm_map_entry that is no longer being referenced. This 661 * function may be called from an interrupt. 662 */ 663 static void 664 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) 665 { 666 struct globaldata *gd = mycpu; 667 668 KKASSERT(map->hint != entry); 669 KKASSERT(map->first_free != entry); 670 671 ++*countp; 672 crit_enter(); 673 entry->next = gd->gd_vme_base; 674 gd->gd_vme_base = entry; 675 crit_exit(); 676 } 677 678 679 /* 680 * vm_map_entry_{un,}link: 681 * 682 * Insert/remove entries from maps. 683 */ 684 static __inline void 685 vm_map_entry_link(vm_map_t map, 686 vm_map_entry_t after_where, 687 vm_map_entry_t entry) 688 { 689 map->nentries++; 690 entry->prev = after_where; 691 entry->next = after_where->next; 692 entry->next->prev = entry; 693 after_where->next = entry; 694 if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) 695 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); 696 } 697 698 static __inline void 699 vm_map_entry_unlink(vm_map_t map, 700 vm_map_entry_t entry) 701 { 702 vm_map_entry_t prev; 703 vm_map_entry_t next; 704 705 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) 706 panic("vm_map_entry_unlink: attempt to mess with locked entry! %p", entry); 707 prev = entry->prev; 708 next = entry->next; 709 next->prev = prev; 710 prev->next = next; 711 vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); 712 map->nentries--; 713 } 714 715 /* 716 * vm_map_lookup_entry: [ internal use only ] 717 * 718 * Finds the map entry containing (or 719 * immediately preceding) the specified address 720 * in the given map; the entry is returned 721 * in the "entry" parameter. The boolean 722 * result indicates whether the address is 723 * actually contained in the map. 724 */ 725 boolean_t 726 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, 727 vm_map_entry_t *entry /* OUT */) 728 { 729 vm_map_entry_t tmp; 730 vm_map_entry_t last; 731 732 #if 0 733 /* 734 * XXX TEMPORARILY DISABLED. For some reason our attempt to revive 735 * the hint code with the red-black lookup meets with system crashes 736 * and lockups. We do not yet know why. 737 * 738 * It is possible that the problem is related to the setting 739 * of the hint during map_entry deletion, in the code specified 740 * at the GGG comment later on in this file. 741 */ 742 /* 743 * Quickly check the cached hint, there's a good chance of a match. 744 */ 745 if (map->hint != &map->header) { 746 tmp = map->hint; 747 if (address >= tmp->start && address < tmp->end) { 748 *entry = tmp; 749 return(TRUE); 750 } 751 } 752 #endif 753 754 /* 755 * Locate the record from the top of the tree. 'last' tracks the 756 * closest prior record and is returned if no match is found, which 757 * in binary tree terms means tracking the most recent right-branch 758 * taken. If there is no prior record, &map->header is returned. 759 */ 760 last = &map->header; 761 tmp = RB_ROOT(&map->rb_root); 762 763 while (tmp) { 764 if (address >= tmp->start) { 765 if (address < tmp->end) { 766 *entry = tmp; 767 map->hint = tmp; 768 return(TRUE); 769 } 770 last = tmp; 771 tmp = RB_RIGHT(tmp, rb_entry); 772 } else { 773 tmp = RB_LEFT(tmp, rb_entry); 774 } 775 } 776 *entry = last; 777 return (FALSE); 778 } 779 780 /* 781 * vm_map_insert: 782 * 783 * Inserts the given whole VM object into the target 784 * map at the specified address range. The object's 785 * size should match that of the address range. 786 * 787 * Requires that the map be locked, and leaves it so. Requires that 788 * sufficient vm_map_entry structures have been reserved and tracks 789 * the use via countp. 790 * 791 * If object is non-NULL, ref count must be bumped by caller 792 * prior to making call to account for the new entry. 793 */ 794 int 795 vm_map_insert(vm_map_t map, int *countp, 796 vm_object_t object, vm_ooffset_t offset, 797 vm_offset_t start, vm_offset_t end, 798 vm_maptype_t maptype, 799 vm_prot_t prot, vm_prot_t max, 800 int cow) 801 { 802 vm_map_entry_t new_entry; 803 vm_map_entry_t prev_entry; 804 vm_map_entry_t temp_entry; 805 vm_eflags_t protoeflags; 806 807 /* 808 * Check that the start and end points are not bogus. 809 */ 810 811 if ((start < map->min_offset) || (end > map->max_offset) || 812 (start >= end)) 813 return (KERN_INVALID_ADDRESS); 814 815 /* 816 * Find the entry prior to the proposed starting address; if it's part 817 * of an existing entry, this range is bogus. 818 */ 819 820 if (vm_map_lookup_entry(map, start, &temp_entry)) 821 return (KERN_NO_SPACE); 822 823 prev_entry = temp_entry; 824 825 /* 826 * Assert that the next entry doesn't overlap the end point. 827 */ 828 829 if ((prev_entry->next != &map->header) && 830 (prev_entry->next->start < end)) 831 return (KERN_NO_SPACE); 832 833 protoeflags = 0; 834 835 if (cow & MAP_COPY_ON_WRITE) 836 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; 837 838 if (cow & MAP_NOFAULT) { 839 protoeflags |= MAP_ENTRY_NOFAULT; 840 841 KASSERT(object == NULL, 842 ("vm_map_insert: paradoxical MAP_NOFAULT request")); 843 } 844 if (cow & MAP_DISABLE_SYNCER) 845 protoeflags |= MAP_ENTRY_NOSYNC; 846 if (cow & MAP_DISABLE_COREDUMP) 847 protoeflags |= MAP_ENTRY_NOCOREDUMP; 848 if (cow & MAP_IS_STACK) 849 protoeflags |= MAP_ENTRY_STACK; 850 851 if (object) { 852 /* 853 * When object is non-NULL, it could be shared with another 854 * process. We have to set or clear OBJ_ONEMAPPING 855 * appropriately. 856 */ 857 if ((object->ref_count > 1) || (object->shadow_count != 0)) { 858 vm_object_clear_flag(object, OBJ_ONEMAPPING); 859 } 860 } 861 else if ((prev_entry != &map->header) && 862 (prev_entry->eflags == protoeflags) && 863 (prev_entry->end == start) && 864 (prev_entry->wired_count == 0) && 865 prev_entry->maptype == maptype && 866 ((prev_entry->object.vm_object == NULL) || 867 vm_object_coalesce(prev_entry->object.vm_object, 868 OFF_TO_IDX(prev_entry->offset), 869 (vm_size_t)(prev_entry->end - prev_entry->start), 870 (vm_size_t)(end - prev_entry->end)))) { 871 /* 872 * We were able to extend the object. Determine if we 873 * can extend the previous map entry to include the 874 * new range as well. 875 */ 876 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && 877 (prev_entry->protection == prot) && 878 (prev_entry->max_protection == max)) { 879 map->size += (end - prev_entry->end); 880 prev_entry->end = end; 881 vm_map_simplify_entry(map, prev_entry, countp); 882 return (KERN_SUCCESS); 883 } 884 885 /* 886 * If we can extend the object but cannot extend the 887 * map entry, we have to create a new map entry. We 888 * must bump the ref count on the extended object to 889 * account for it. object may be NULL. 890 */ 891 object = prev_entry->object.vm_object; 892 offset = prev_entry->offset + 893 (prev_entry->end - prev_entry->start); 894 vm_object_reference(object); 895 } 896 897 /* 898 * NOTE: if conditionals fail, object can be NULL here. This occurs 899 * in things like the buffer map where we manage kva but do not manage 900 * backing objects. 901 */ 902 903 /* 904 * Create a new entry 905 */ 906 907 new_entry = vm_map_entry_create(map, countp); 908 new_entry->start = start; 909 new_entry->end = end; 910 911 new_entry->maptype = maptype; 912 new_entry->eflags = protoeflags; 913 new_entry->object.vm_object = object; 914 new_entry->offset = offset; 915 new_entry->aux.master_pde = 0; 916 917 new_entry->inheritance = VM_INHERIT_DEFAULT; 918 new_entry->protection = prot; 919 new_entry->max_protection = max; 920 new_entry->wired_count = 0; 921 922 /* 923 * Insert the new entry into the list 924 */ 925 926 vm_map_entry_link(map, prev_entry, new_entry); 927 map->size += new_entry->end - new_entry->start; 928 929 /* 930 * Update the free space hint 931 */ 932 if ((map->first_free == prev_entry) && 933 (prev_entry->end >= new_entry->start)) { 934 map->first_free = new_entry; 935 } 936 937 #if 0 938 /* 939 * Temporarily removed to avoid MAP_STACK panic, due to 940 * MAP_STACK being a huge hack. Will be added back in 941 * when MAP_STACK (and the user stack mapping) is fixed. 942 */ 943 /* 944 * It may be possible to simplify the entry 945 */ 946 vm_map_simplify_entry(map, new_entry, countp); 947 #endif 948 949 /* 950 * Try to pre-populate the page table. Mappings governed by virtual 951 * page tables cannot be prepopulated without a lot of work, so 952 * don't try. 953 */ 954 if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) && 955 maptype != VM_MAPTYPE_VPAGETABLE) { 956 pmap_object_init_pt(map->pmap, start, prot, 957 object, OFF_TO_IDX(offset), end - start, 958 cow & MAP_PREFAULT_PARTIAL); 959 } 960 961 return (KERN_SUCCESS); 962 } 963 964 /* 965 * Find sufficient space for `length' bytes in the given map, starting at 966 * `start'. The map must be locked. Returns 0 on success, 1 on no space. 967 * 968 * This function will returned an arbitrarily aligned pointer. If no 969 * particular alignment is required you should pass align as 1. Note that 970 * the map may return PAGE_SIZE aligned pointers if all the lengths used in 971 * the map are a multiple of PAGE_SIZE, even if you pass a smaller align 972 * argument. 973 * 974 * 'align' should be a power of 2 but is not required to be. 975 */ 976 int 977 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, 978 vm_offset_t align, int flags, vm_offset_t *addr) 979 { 980 vm_map_entry_t entry, next; 981 vm_offset_t end; 982 vm_offset_t align_mask; 983 984 if (start < map->min_offset) 985 start = map->min_offset; 986 if (start > map->max_offset) 987 return (1); 988 989 /* 990 * If the alignment is not a power of 2 we will have to use 991 * a mod/division, set align_mask to a special value. 992 */ 993 if ((align | (align - 1)) + 1 != (align << 1)) 994 align_mask = (vm_offset_t)-1; 995 else 996 align_mask = align - 1; 997 998 retry: 999 /* 1000 * Look for the first possible address; if there's already something 1001 * at this address, we have to start after it. 1002 */ 1003 if (start == map->min_offset) { 1004 if ((entry = map->first_free) != &map->header) 1005 start = entry->end; 1006 } else { 1007 vm_map_entry_t tmp; 1008 1009 if (vm_map_lookup_entry(map, start, &tmp)) 1010 start = tmp->end; 1011 entry = tmp; 1012 } 1013 1014 /* 1015 * Look through the rest of the map, trying to fit a new region in the 1016 * gap between existing regions, or after the very last region. 1017 */ 1018 for (;; start = (entry = next)->end) { 1019 /* 1020 * Adjust the proposed start by the requested alignment, 1021 * be sure that we didn't wrap the address. 1022 */ 1023 if (align_mask == (vm_offset_t)-1) 1024 end = ((start + align - 1) / align) * align; 1025 else 1026 end = (start + align_mask) & ~align_mask; 1027 if (end < start) 1028 return (1); 1029 start = end; 1030 /* 1031 * Find the end of the proposed new region. Be sure we didn't 1032 * go beyond the end of the map, or wrap around the address. 1033 * Then check to see if this is the last entry or if the 1034 * proposed end fits in the gap between this and the next 1035 * entry. 1036 */ 1037 end = start + length; 1038 if (end > map->max_offset || end < start) 1039 return (1); 1040 next = entry->next; 1041 1042 /* 1043 * If the next entry's start address is beyond the desired 1044 * end address we may have found a good entry. 1045 * 1046 * If the next entry is a stack mapping we do not map into 1047 * the stack's reserved space. 1048 * 1049 * XXX continue to allow mapping into the stack's reserved 1050 * space if doing a MAP_STACK mapping inside a MAP_STACK 1051 * mapping, for backwards compatibility. But the caller 1052 * really should use MAP_STACK | MAP_TRYFIXED if they 1053 * want to do that. 1054 */ 1055 if (next == &map->header) 1056 break; 1057 if (next->start >= end) { 1058 if ((next->eflags & MAP_ENTRY_STACK) == 0) 1059 break; 1060 if (flags & MAP_STACK) 1061 break; 1062 if (next->start - next->aux.avail_ssize >= end) 1063 break; 1064 } 1065 } 1066 map->hint = entry; 1067 if (map == &kernel_map) { 1068 vm_offset_t ksize; 1069 if ((ksize = round_page(start + length)) > kernel_vm_end) { 1070 pmap_growkernel(ksize); 1071 goto retry; 1072 } 1073 } 1074 *addr = start; 1075 return (0); 1076 } 1077 1078 /* 1079 * vm_map_find finds an unallocated region in the target address 1080 * map with the given length. The search is defined to be 1081 * first-fit from the specified address; the region found is 1082 * returned in the same parameter. 1083 * 1084 * If object is non-NULL, ref count must be bumped by caller 1085 * prior to making call to account for the new entry. 1086 */ 1087 int 1088 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 1089 vm_offset_t *addr, vm_size_t length, 1090 boolean_t fitit, 1091 vm_maptype_t maptype, 1092 vm_prot_t prot, vm_prot_t max, 1093 int cow) 1094 { 1095 vm_offset_t start; 1096 int result; 1097 int count; 1098 1099 start = *addr; 1100 1101 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1102 vm_map_lock(map); 1103 if (fitit) { 1104 if (vm_map_findspace(map, start, length, 1, 0, addr)) { 1105 vm_map_unlock(map); 1106 vm_map_entry_release(count); 1107 return (KERN_NO_SPACE); 1108 } 1109 start = *addr; 1110 } 1111 result = vm_map_insert(map, &count, object, offset, 1112 start, start + length, 1113 maptype, 1114 prot, max, 1115 cow); 1116 vm_map_unlock(map); 1117 vm_map_entry_release(count); 1118 1119 return (result); 1120 } 1121 1122 /* 1123 * vm_map_simplify_entry: 1124 * 1125 * Simplify the given map entry by merging with either neighbor. This 1126 * routine also has the ability to merge with both neighbors. 1127 * 1128 * The map must be locked. 1129 * 1130 * This routine guarentees that the passed entry remains valid (though 1131 * possibly extended). When merging, this routine may delete one or 1132 * both neighbors. No action is taken on entries which have their 1133 * in-transition flag set. 1134 */ 1135 void 1136 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp) 1137 { 1138 vm_map_entry_t next, prev; 1139 vm_size_t prevsize, esize; 1140 1141 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1142 ++mycpu->gd_cnt.v_intrans_coll; 1143 return; 1144 } 1145 1146 if (entry->maptype == VM_MAPTYPE_SUBMAP) 1147 return; 1148 1149 prev = entry->prev; 1150 if (prev != &map->header) { 1151 prevsize = prev->end - prev->start; 1152 if ( (prev->end == entry->start) && 1153 (prev->maptype == entry->maptype) && 1154 (prev->object.vm_object == entry->object.vm_object) && 1155 (!prev->object.vm_object || 1156 (prev->offset + prevsize == entry->offset)) && 1157 (prev->eflags == entry->eflags) && 1158 (prev->protection == entry->protection) && 1159 (prev->max_protection == entry->max_protection) && 1160 (prev->inheritance == entry->inheritance) && 1161 (prev->wired_count == entry->wired_count)) { 1162 if (map->first_free == prev) 1163 map->first_free = entry; 1164 if (map->hint == prev) 1165 map->hint = entry; 1166 vm_map_entry_unlink(map, prev); 1167 entry->start = prev->start; 1168 entry->offset = prev->offset; 1169 if (prev->object.vm_object) 1170 vm_object_deallocate(prev->object.vm_object); 1171 vm_map_entry_dispose(map, prev, countp); 1172 } 1173 } 1174 1175 next = entry->next; 1176 if (next != &map->header) { 1177 esize = entry->end - entry->start; 1178 if ((entry->end == next->start) && 1179 (next->maptype == entry->maptype) && 1180 (next->object.vm_object == entry->object.vm_object) && 1181 (!entry->object.vm_object || 1182 (entry->offset + esize == next->offset)) && 1183 (next->eflags == entry->eflags) && 1184 (next->protection == entry->protection) && 1185 (next->max_protection == entry->max_protection) && 1186 (next->inheritance == entry->inheritance) && 1187 (next->wired_count == entry->wired_count)) { 1188 if (map->first_free == next) 1189 map->first_free = entry; 1190 if (map->hint == next) 1191 map->hint = entry; 1192 vm_map_entry_unlink(map, next); 1193 entry->end = next->end; 1194 if (next->object.vm_object) 1195 vm_object_deallocate(next->object.vm_object); 1196 vm_map_entry_dispose(map, next, countp); 1197 } 1198 } 1199 } 1200 /* 1201 * vm_map_clip_start: [ internal use only ] 1202 * 1203 * Asserts that the given entry begins at or after 1204 * the specified address; if necessary, 1205 * it splits the entry into two. 1206 */ 1207 #define vm_map_clip_start(map, entry, startaddr, countp) \ 1208 { \ 1209 if (startaddr > entry->start) \ 1210 _vm_map_clip_start(map, entry, startaddr, countp); \ 1211 } 1212 1213 /* 1214 * This routine is called only when it is known that 1215 * the entry must be split. 1216 */ 1217 static void 1218 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start, int *countp) 1219 { 1220 vm_map_entry_t new_entry; 1221 1222 /* 1223 * Split off the front portion -- note that we must insert the new 1224 * entry BEFORE this one, so that this entry has the specified 1225 * starting address. 1226 */ 1227 1228 vm_map_simplify_entry(map, entry, countp); 1229 1230 /* 1231 * If there is no object backing this entry, we might as well create 1232 * one now. If we defer it, an object can get created after the map 1233 * is clipped, and individual objects will be created for the split-up 1234 * map. This is a bit of a hack, but is also about the best place to 1235 * put this improvement. 1236 */ 1237 if (entry->object.vm_object == NULL && !map->system_map) { 1238 vm_map_entry_allocate_object(entry); 1239 } 1240 1241 new_entry = vm_map_entry_create(map, countp); 1242 *new_entry = *entry; 1243 1244 new_entry->end = start; 1245 entry->offset += (start - entry->start); 1246 entry->start = start; 1247 1248 vm_map_entry_link(map, entry->prev, new_entry); 1249 1250 switch(entry->maptype) { 1251 case VM_MAPTYPE_NORMAL: 1252 case VM_MAPTYPE_VPAGETABLE: 1253 vm_object_reference(new_entry->object.vm_object); 1254 break; 1255 default: 1256 break; 1257 } 1258 } 1259 1260 /* 1261 * vm_map_clip_end: [ internal use only ] 1262 * 1263 * Asserts that the given entry ends at or before 1264 * the specified address; if necessary, 1265 * it splits the entry into two. 1266 */ 1267 1268 #define vm_map_clip_end(map, entry, endaddr, countp) \ 1269 { \ 1270 if (endaddr < entry->end) \ 1271 _vm_map_clip_end(map, entry, endaddr, countp); \ 1272 } 1273 1274 /* 1275 * This routine is called only when it is known that 1276 * the entry must be split. 1277 */ 1278 static void 1279 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end, int *countp) 1280 { 1281 vm_map_entry_t new_entry; 1282 1283 /* 1284 * If there is no object backing this entry, we might as well create 1285 * one now. If we defer it, an object can get created after the map 1286 * is clipped, and individual objects will be created for the split-up 1287 * map. This is a bit of a hack, but is also about the best place to 1288 * put this improvement. 1289 */ 1290 1291 if (entry->object.vm_object == NULL && !map->system_map) { 1292 vm_map_entry_allocate_object(entry); 1293 } 1294 1295 /* 1296 * Create a new entry and insert it AFTER the specified entry 1297 */ 1298 1299 new_entry = vm_map_entry_create(map, countp); 1300 *new_entry = *entry; 1301 1302 new_entry->start = entry->end = end; 1303 new_entry->offset += (end - entry->start); 1304 1305 vm_map_entry_link(map, entry, new_entry); 1306 1307 switch(entry->maptype) { 1308 case VM_MAPTYPE_NORMAL: 1309 case VM_MAPTYPE_VPAGETABLE: 1310 vm_object_reference(new_entry->object.vm_object); 1311 break; 1312 default: 1313 break; 1314 } 1315 } 1316 1317 /* 1318 * VM_MAP_RANGE_CHECK: [ internal use only ] 1319 * 1320 * Asserts that the starting and ending region 1321 * addresses fall within the valid range of the map. 1322 */ 1323 #define VM_MAP_RANGE_CHECK(map, start, end) \ 1324 { \ 1325 if (start < vm_map_min(map)) \ 1326 start = vm_map_min(map); \ 1327 if (end > vm_map_max(map)) \ 1328 end = vm_map_max(map); \ 1329 if (start > end) \ 1330 start = end; \ 1331 } 1332 1333 /* 1334 * vm_map_transition_wait: [ kernel use only ] 1335 * 1336 * Used to block when an in-transition collison occurs. The map 1337 * is unlocked for the sleep and relocked before the return. 1338 */ 1339 static 1340 void 1341 vm_map_transition_wait(vm_map_t map) 1342 { 1343 vm_map_unlock(map); 1344 tsleep(map, 0, "vment", 0); 1345 vm_map_lock(map); 1346 } 1347 1348 /* 1349 * CLIP_CHECK_BACK 1350 * CLIP_CHECK_FWD 1351 * 1352 * When we do blocking operations with the map lock held it is 1353 * possible that a clip might have occured on our in-transit entry, 1354 * requiring an adjustment to the entry in our loop. These macros 1355 * help the pageable and clip_range code deal with the case. The 1356 * conditional costs virtually nothing if no clipping has occured. 1357 */ 1358 1359 #define CLIP_CHECK_BACK(entry, save_start) \ 1360 do { \ 1361 while (entry->start != save_start) { \ 1362 entry = entry->prev; \ 1363 KASSERT(entry != &map->header, ("bad entry clip")); \ 1364 } \ 1365 } while(0) 1366 1367 #define CLIP_CHECK_FWD(entry, save_end) \ 1368 do { \ 1369 while (entry->end != save_end) { \ 1370 entry = entry->next; \ 1371 KASSERT(entry != &map->header, ("bad entry clip")); \ 1372 } \ 1373 } while(0) 1374 1375 1376 /* 1377 * vm_map_clip_range: [ kernel use only ] 1378 * 1379 * Clip the specified range and return the base entry. The 1380 * range may cover several entries starting at the returned base 1381 * and the first and last entry in the covering sequence will be 1382 * properly clipped to the requested start and end address. 1383 * 1384 * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES 1385 * flag. 1386 * 1387 * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries 1388 * covered by the requested range. 1389 * 1390 * The map must be exclusively locked on entry and will remain locked 1391 * on return. If no range exists or the range contains holes and you 1392 * specified that no holes were allowed, NULL will be returned. This 1393 * routine may temporarily unlock the map in order avoid a deadlock when 1394 * sleeping. 1395 */ 1396 static 1397 vm_map_entry_t 1398 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, 1399 int *countp, int flags) 1400 { 1401 vm_map_entry_t start_entry; 1402 vm_map_entry_t entry; 1403 1404 /* 1405 * Locate the entry and effect initial clipping. The in-transition 1406 * case does not occur very often so do not try to optimize it. 1407 */ 1408 again: 1409 if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) 1410 return (NULL); 1411 entry = start_entry; 1412 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 1413 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1414 ++mycpu->gd_cnt.v_intrans_coll; 1415 ++mycpu->gd_cnt.v_intrans_wait; 1416 vm_map_transition_wait(map); 1417 /* 1418 * entry and/or start_entry may have been clipped while 1419 * we slept, or may have gone away entirely. We have 1420 * to restart from the lookup. 1421 */ 1422 goto again; 1423 } 1424 /* 1425 * Since we hold an exclusive map lock we do not have to restart 1426 * after clipping, even though clipping may block in zalloc. 1427 */ 1428 vm_map_clip_start(map, entry, start, countp); 1429 vm_map_clip_end(map, entry, end, countp); 1430 entry->eflags |= MAP_ENTRY_IN_TRANSITION; 1431 1432 /* 1433 * Scan entries covered by the range. When working on the next 1434 * entry a restart need only re-loop on the current entry which 1435 * we have already locked, since 'next' may have changed. Also, 1436 * even though entry is safe, it may have been clipped so we 1437 * have to iterate forwards through the clip after sleeping. 1438 */ 1439 while (entry->next != &map->header && entry->next->start < end) { 1440 vm_map_entry_t next = entry->next; 1441 1442 if (flags & MAP_CLIP_NO_HOLES) { 1443 if (next->start > entry->end) { 1444 vm_map_unclip_range(map, start_entry, 1445 start, entry->end, countp, flags); 1446 return(NULL); 1447 } 1448 } 1449 1450 if (next->eflags & MAP_ENTRY_IN_TRANSITION) { 1451 vm_offset_t save_end = entry->end; 1452 next->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 1453 ++mycpu->gd_cnt.v_intrans_coll; 1454 ++mycpu->gd_cnt.v_intrans_wait; 1455 vm_map_transition_wait(map); 1456 1457 /* 1458 * clips might have occured while we blocked. 1459 */ 1460 CLIP_CHECK_FWD(entry, save_end); 1461 CLIP_CHECK_BACK(start_entry, start); 1462 continue; 1463 } 1464 /* 1465 * No restart necessary even though clip_end may block, we 1466 * are holding the map lock. 1467 */ 1468 vm_map_clip_end(map, next, end, countp); 1469 next->eflags |= MAP_ENTRY_IN_TRANSITION; 1470 entry = next; 1471 } 1472 if (flags & MAP_CLIP_NO_HOLES) { 1473 if (entry->end != end) { 1474 vm_map_unclip_range(map, start_entry, 1475 start, entry->end, countp, flags); 1476 return(NULL); 1477 } 1478 } 1479 return(start_entry); 1480 } 1481 1482 /* 1483 * vm_map_unclip_range: [ kernel use only ] 1484 * 1485 * Undo the effect of vm_map_clip_range(). You should pass the same 1486 * flags and the same range that you passed to vm_map_clip_range(). 1487 * This code will clear the in-transition flag on the entries and 1488 * wake up anyone waiting. This code will also simplify the sequence 1489 * and attempt to merge it with entries before and after the sequence. 1490 * 1491 * The map must be locked on entry and will remain locked on return. 1492 * 1493 * Note that you should also pass the start_entry returned by 1494 * vm_map_clip_range(). However, if you block between the two calls 1495 * with the map unlocked please be aware that the start_entry may 1496 * have been clipped and you may need to scan it backwards to find 1497 * the entry corresponding with the original start address. You are 1498 * responsible for this, vm_map_unclip_range() expects the correct 1499 * start_entry to be passed to it and will KASSERT otherwise. 1500 */ 1501 static 1502 void 1503 vm_map_unclip_range( 1504 vm_map_t map, 1505 vm_map_entry_t start_entry, 1506 vm_offset_t start, 1507 vm_offset_t end, 1508 int *countp, 1509 int flags) 1510 { 1511 vm_map_entry_t entry; 1512 1513 entry = start_entry; 1514 1515 KASSERT(entry->start == start, ("unclip_range: illegal base entry")); 1516 while (entry != &map->header && entry->start < end) { 1517 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, ("in-transition flag not set during unclip on: %p", entry)); 1518 KASSERT(entry->end <= end, ("unclip_range: tail wasn't clipped")); 1519 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; 1520 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { 1521 entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; 1522 wakeup(map); 1523 } 1524 entry = entry->next; 1525 } 1526 1527 /* 1528 * Simplification does not block so there is no restart case. 1529 */ 1530 entry = start_entry; 1531 while (entry != &map->header && entry->start < end) { 1532 vm_map_simplify_entry(map, entry, countp); 1533 entry = entry->next; 1534 } 1535 } 1536 1537 /* 1538 * vm_map_submap: [ kernel use only ] 1539 * 1540 * Mark the given range as handled by a subordinate map. 1541 * 1542 * This range must have been created with vm_map_find, 1543 * and no other operations may have been performed on this 1544 * range prior to calling vm_map_submap. 1545 * 1546 * Only a limited number of operations can be performed 1547 * within this rage after calling vm_map_submap: 1548 * vm_fault 1549 * [Don't try vm_map_copy!] 1550 * 1551 * To remove a submapping, one must first remove the 1552 * range from the superior map, and then destroy the 1553 * submap (if desired). [Better yet, don't try it.] 1554 */ 1555 int 1556 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) 1557 { 1558 vm_map_entry_t entry; 1559 int result = KERN_INVALID_ARGUMENT; 1560 int count; 1561 1562 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1563 vm_map_lock(map); 1564 1565 VM_MAP_RANGE_CHECK(map, start, end); 1566 1567 if (vm_map_lookup_entry(map, start, &entry)) { 1568 vm_map_clip_start(map, entry, start, &count); 1569 } else { 1570 entry = entry->next; 1571 } 1572 1573 vm_map_clip_end(map, entry, end, &count); 1574 1575 if ((entry->start == start) && (entry->end == end) && 1576 ((entry->eflags & MAP_ENTRY_COW) == 0) && 1577 (entry->object.vm_object == NULL)) { 1578 entry->object.sub_map = submap; 1579 entry->maptype = VM_MAPTYPE_SUBMAP; 1580 result = KERN_SUCCESS; 1581 } 1582 vm_map_unlock(map); 1583 vm_map_entry_release(count); 1584 1585 return (result); 1586 } 1587 1588 /* 1589 * vm_map_protect: 1590 * 1591 * Sets the protection of the specified address region in the target map. 1592 * If "set_max" is specified, the maximum protection is to be set; 1593 * otherwise, only the current protection is affected. 1594 * 1595 * The protection is not applicable to submaps, but is applicable to normal 1596 * maps and maps governed by virtual page tables. For example, when operating 1597 * on a virtual page table our protection basically controls how COW occurs 1598 * on the backing object, whereas the virtual page table abstraction itself 1599 * is an abstraction for userland. 1600 */ 1601 int 1602 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, 1603 vm_prot_t new_prot, boolean_t set_max) 1604 { 1605 vm_map_entry_t current; 1606 vm_map_entry_t entry; 1607 int count; 1608 1609 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1610 vm_map_lock(map); 1611 1612 VM_MAP_RANGE_CHECK(map, start, end); 1613 1614 if (vm_map_lookup_entry(map, start, &entry)) { 1615 vm_map_clip_start(map, entry, start, &count); 1616 } else { 1617 entry = entry->next; 1618 } 1619 1620 /* 1621 * Make a first pass to check for protection violations. 1622 */ 1623 current = entry; 1624 while ((current != &map->header) && (current->start < end)) { 1625 if (current->maptype == VM_MAPTYPE_SUBMAP) { 1626 vm_map_unlock(map); 1627 vm_map_entry_release(count); 1628 return (KERN_INVALID_ARGUMENT); 1629 } 1630 if ((new_prot & current->max_protection) != new_prot) { 1631 vm_map_unlock(map); 1632 vm_map_entry_release(count); 1633 return (KERN_PROTECTION_FAILURE); 1634 } 1635 current = current->next; 1636 } 1637 1638 /* 1639 * Go back and fix up protections. [Note that clipping is not 1640 * necessary the second time.] 1641 */ 1642 current = entry; 1643 1644 while ((current != &map->header) && (current->start < end)) { 1645 vm_prot_t old_prot; 1646 1647 vm_map_clip_end(map, current, end, &count); 1648 1649 old_prot = current->protection; 1650 if (set_max) { 1651 current->protection = 1652 (current->max_protection = new_prot) & 1653 old_prot; 1654 } else { 1655 current->protection = new_prot; 1656 } 1657 1658 /* 1659 * Update physical map if necessary. Worry about copy-on-write 1660 * here -- CHECK THIS XXX 1661 */ 1662 1663 if (current->protection != old_prot) { 1664 #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ 1665 VM_PROT_ALL) 1666 1667 pmap_protect(map->pmap, current->start, 1668 current->end, 1669 current->protection & MASK(current)); 1670 #undef MASK 1671 } 1672 1673 vm_map_simplify_entry(map, current, &count); 1674 1675 current = current->next; 1676 } 1677 1678 vm_map_unlock(map); 1679 vm_map_entry_release(count); 1680 return (KERN_SUCCESS); 1681 } 1682 1683 /* 1684 * vm_map_madvise: 1685 * 1686 * This routine traverses a processes map handling the madvise 1687 * system call. Advisories are classified as either those effecting 1688 * the vm_map_entry structure, or those effecting the underlying 1689 * objects. 1690 * 1691 * The <value> argument is used for extended madvise calls. 1692 */ 1693 int 1694 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end, 1695 int behav, off_t value) 1696 { 1697 vm_map_entry_t current, entry; 1698 int modify_map = 0; 1699 int error = 0; 1700 int count; 1701 1702 /* 1703 * Some madvise calls directly modify the vm_map_entry, in which case 1704 * we need to use an exclusive lock on the map and we need to perform 1705 * various clipping operations. Otherwise we only need a read-lock 1706 * on the map. 1707 */ 1708 1709 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1710 1711 switch(behav) { 1712 case MADV_NORMAL: 1713 case MADV_SEQUENTIAL: 1714 case MADV_RANDOM: 1715 case MADV_NOSYNC: 1716 case MADV_AUTOSYNC: 1717 case MADV_NOCORE: 1718 case MADV_CORE: 1719 case MADV_SETMAP: 1720 case MADV_INVAL: 1721 modify_map = 1; 1722 vm_map_lock(map); 1723 break; 1724 case MADV_WILLNEED: 1725 case MADV_DONTNEED: 1726 case MADV_FREE: 1727 vm_map_lock_read(map); 1728 break; 1729 default: 1730 vm_map_entry_release(count); 1731 return (EINVAL); 1732 } 1733 1734 /* 1735 * Locate starting entry and clip if necessary. 1736 */ 1737 1738 VM_MAP_RANGE_CHECK(map, start, end); 1739 1740 if (vm_map_lookup_entry(map, start, &entry)) { 1741 if (modify_map) 1742 vm_map_clip_start(map, entry, start, &count); 1743 } else { 1744 entry = entry->next; 1745 } 1746 1747 if (modify_map) { 1748 /* 1749 * madvise behaviors that are implemented in the vm_map_entry. 1750 * 1751 * We clip the vm_map_entry so that behavioral changes are 1752 * limited to the specified address range. 1753 */ 1754 for (current = entry; 1755 (current != &map->header) && (current->start < end); 1756 current = current->next 1757 ) { 1758 if (current->maptype == VM_MAPTYPE_SUBMAP) 1759 continue; 1760 1761 vm_map_clip_end(map, current, end, &count); 1762 1763 switch (behav) { 1764 case MADV_NORMAL: 1765 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); 1766 break; 1767 case MADV_SEQUENTIAL: 1768 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); 1769 break; 1770 case MADV_RANDOM: 1771 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); 1772 break; 1773 case MADV_NOSYNC: 1774 current->eflags |= MAP_ENTRY_NOSYNC; 1775 break; 1776 case MADV_AUTOSYNC: 1777 current->eflags &= ~MAP_ENTRY_NOSYNC; 1778 break; 1779 case MADV_NOCORE: 1780 current->eflags |= MAP_ENTRY_NOCOREDUMP; 1781 break; 1782 case MADV_CORE: 1783 current->eflags &= ~MAP_ENTRY_NOCOREDUMP; 1784 break; 1785 case MADV_INVAL: 1786 /* 1787 * Invalidate the related pmap entries, used 1788 * to flush portions of the real kernel's 1789 * pmap when the caller has removed or 1790 * modified existing mappings in a virtual 1791 * page table. 1792 */ 1793 pmap_remove(map->pmap, 1794 current->start, current->end); 1795 break; 1796 case MADV_SETMAP: 1797 /* 1798 * Set the page directory page for a map 1799 * governed by a virtual page table. Mark 1800 * the entry as being governed by a virtual 1801 * page table if it is not. 1802 * 1803 * XXX the page directory page is stored 1804 * in the avail_ssize field if the map_entry. 1805 * 1806 * XXX the map simplification code does not 1807 * compare this field so weird things may 1808 * happen if you do not apply this function 1809 * to the entire mapping governed by the 1810 * virtual page table. 1811 */ 1812 if (current->maptype != VM_MAPTYPE_VPAGETABLE) { 1813 error = EINVAL; 1814 break; 1815 } 1816 current->aux.master_pde = value; 1817 pmap_remove(map->pmap, 1818 current->start, current->end); 1819 break; 1820 default: 1821 error = EINVAL; 1822 break; 1823 } 1824 vm_map_simplify_entry(map, current, &count); 1825 } 1826 vm_map_unlock(map); 1827 } else { 1828 vm_pindex_t pindex; 1829 int count; 1830 1831 /* 1832 * madvise behaviors that are implemented in the underlying 1833 * vm_object. 1834 * 1835 * Since we don't clip the vm_map_entry, we have to clip 1836 * the vm_object pindex and count. 1837 * 1838 * NOTE! We currently do not support these functions on 1839 * virtual page tables. 1840 */ 1841 for (current = entry; 1842 (current != &map->header) && (current->start < end); 1843 current = current->next 1844 ) { 1845 vm_offset_t useStart; 1846 1847 if (current->maptype != VM_MAPTYPE_NORMAL) 1848 continue; 1849 1850 pindex = OFF_TO_IDX(current->offset); 1851 count = atop(current->end - current->start); 1852 useStart = current->start; 1853 1854 if (current->start < start) { 1855 pindex += atop(start - current->start); 1856 count -= atop(start - current->start); 1857 useStart = start; 1858 } 1859 if (current->end > end) 1860 count -= atop(current->end - end); 1861 1862 if (count <= 0) 1863 continue; 1864 1865 vm_object_madvise(current->object.vm_object, 1866 pindex, count, behav); 1867 1868 /* 1869 * Try to populate the page table. Mappings governed 1870 * by virtual page tables cannot be pre-populated 1871 * without a lot of work so don't try. 1872 */ 1873 if (behav == MADV_WILLNEED && 1874 current->maptype != VM_MAPTYPE_VPAGETABLE) { 1875 pmap_object_init_pt( 1876 map->pmap, 1877 useStart, 1878 current->protection, 1879 current->object.vm_object, 1880 pindex, 1881 (count << PAGE_SHIFT), 1882 MAP_PREFAULT_MADVISE 1883 ); 1884 } 1885 } 1886 vm_map_unlock_read(map); 1887 } 1888 vm_map_entry_release(count); 1889 return(error); 1890 } 1891 1892 1893 /* 1894 * vm_map_inherit: 1895 * 1896 * Sets the inheritance of the specified address 1897 * range in the target map. Inheritance 1898 * affects how the map will be shared with 1899 * child maps at the time of vm_map_fork. 1900 */ 1901 int 1902 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, 1903 vm_inherit_t new_inheritance) 1904 { 1905 vm_map_entry_t entry; 1906 vm_map_entry_t temp_entry; 1907 int count; 1908 1909 switch (new_inheritance) { 1910 case VM_INHERIT_NONE: 1911 case VM_INHERIT_COPY: 1912 case VM_INHERIT_SHARE: 1913 break; 1914 default: 1915 return (KERN_INVALID_ARGUMENT); 1916 } 1917 1918 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1919 vm_map_lock(map); 1920 1921 VM_MAP_RANGE_CHECK(map, start, end); 1922 1923 if (vm_map_lookup_entry(map, start, &temp_entry)) { 1924 entry = temp_entry; 1925 vm_map_clip_start(map, entry, start, &count); 1926 } else 1927 entry = temp_entry->next; 1928 1929 while ((entry != &map->header) && (entry->start < end)) { 1930 vm_map_clip_end(map, entry, end, &count); 1931 1932 entry->inheritance = new_inheritance; 1933 1934 vm_map_simplify_entry(map, entry, &count); 1935 1936 entry = entry->next; 1937 } 1938 vm_map_unlock(map); 1939 vm_map_entry_release(count); 1940 return (KERN_SUCCESS); 1941 } 1942 1943 /* 1944 * Implement the semantics of mlock 1945 */ 1946 int 1947 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, 1948 boolean_t new_pageable) 1949 { 1950 vm_map_entry_t entry; 1951 vm_map_entry_t start_entry; 1952 vm_offset_t end; 1953 int rv = KERN_SUCCESS; 1954 int count; 1955 1956 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 1957 vm_map_lock(map); 1958 VM_MAP_RANGE_CHECK(map, start, real_end); 1959 end = real_end; 1960 1961 start_entry = vm_map_clip_range(map, start, end, &count, MAP_CLIP_NO_HOLES); 1962 if (start_entry == NULL) { 1963 vm_map_unlock(map); 1964 vm_map_entry_release(count); 1965 return (KERN_INVALID_ADDRESS); 1966 } 1967 1968 if (new_pageable == 0) { 1969 entry = start_entry; 1970 while ((entry != &map->header) && (entry->start < end)) { 1971 vm_offset_t save_start; 1972 vm_offset_t save_end; 1973 1974 /* 1975 * Already user wired or hard wired (trivial cases) 1976 */ 1977 if (entry->eflags & MAP_ENTRY_USER_WIRED) { 1978 entry = entry->next; 1979 continue; 1980 } 1981 if (entry->wired_count != 0) { 1982 entry->wired_count++; 1983 entry->eflags |= MAP_ENTRY_USER_WIRED; 1984 entry = entry->next; 1985 continue; 1986 } 1987 1988 /* 1989 * A new wiring requires instantiation of appropriate 1990 * management structures and the faulting in of the 1991 * page. 1992 */ 1993 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 1994 int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY; 1995 if (copyflag && ((entry->protection & VM_PROT_WRITE) != 0)) { 1996 vm_map_entry_shadow(entry); 1997 } else if (entry->object.vm_object == NULL && 1998 !map->system_map) { 1999 vm_map_entry_allocate_object(entry); 2000 } 2001 } 2002 entry->wired_count++; 2003 entry->eflags |= MAP_ENTRY_USER_WIRED; 2004 2005 /* 2006 * Now fault in the area. Note that vm_fault_wire() 2007 * may release the map lock temporarily, it will be 2008 * relocked on return. The in-transition 2009 * flag protects the entries. 2010 */ 2011 save_start = entry->start; 2012 save_end = entry->end; 2013 rv = vm_fault_wire(map, entry, TRUE); 2014 if (rv) { 2015 CLIP_CHECK_BACK(entry, save_start); 2016 for (;;) { 2017 KASSERT(entry->wired_count == 1, ("bad wired_count on entry")); 2018 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2019 entry->wired_count = 0; 2020 if (entry->end == save_end) 2021 break; 2022 entry = entry->next; 2023 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2024 } 2025 end = save_start; /* unwire the rest */ 2026 break; 2027 } 2028 /* 2029 * note that even though the entry might have been 2030 * clipped, the USER_WIRED flag we set prevents 2031 * duplication so we do not have to do a 2032 * clip check. 2033 */ 2034 entry = entry->next; 2035 } 2036 2037 /* 2038 * If we failed fall through to the unwiring section to 2039 * unwire what we had wired so far. 'end' has already 2040 * been adjusted. 2041 */ 2042 if (rv) 2043 new_pageable = 1; 2044 2045 /* 2046 * start_entry might have been clipped if we unlocked the 2047 * map and blocked. No matter how clipped it has gotten 2048 * there should be a fragment that is on our start boundary. 2049 */ 2050 CLIP_CHECK_BACK(start_entry, start); 2051 } 2052 2053 /* 2054 * Deal with the unwiring case. 2055 */ 2056 if (new_pageable) { 2057 /* 2058 * This is the unwiring case. We must first ensure that the 2059 * range to be unwired is really wired down. We know there 2060 * are no holes. 2061 */ 2062 entry = start_entry; 2063 while ((entry != &map->header) && (entry->start < end)) { 2064 if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { 2065 rv = KERN_INVALID_ARGUMENT; 2066 goto done; 2067 } 2068 KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry)); 2069 entry = entry->next; 2070 } 2071 2072 /* 2073 * Now decrement the wiring count for each region. If a region 2074 * becomes completely unwired, unwire its physical pages and 2075 * mappings. 2076 */ 2077 /* 2078 * The map entries are processed in a loop, checking to 2079 * make sure the entry is wired and asserting it has a wired 2080 * count. However, another loop was inserted more-or-less in 2081 * the middle of the unwiring path. This loop picks up the 2082 * "entry" loop variable from the first loop without first 2083 * setting it to start_entry. Naturally, the secound loop 2084 * is never entered and the pages backing the entries are 2085 * never unwired. This can lead to a leak of wired pages. 2086 */ 2087 entry = start_entry; 2088 while ((entry != &map->header) && (entry->start < end)) { 2089 KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, 2090 ("expected USER_WIRED on entry %p", entry)); 2091 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2092 entry->wired_count--; 2093 if (entry->wired_count == 0) 2094 vm_fault_unwire(map, entry); 2095 entry = entry->next; 2096 } 2097 } 2098 done: 2099 vm_map_unclip_range(map, start_entry, start, real_end, &count, 2100 MAP_CLIP_NO_HOLES); 2101 map->timestamp++; 2102 vm_map_unlock(map); 2103 vm_map_entry_release(count); 2104 return (rv); 2105 } 2106 2107 /* 2108 * vm_map_wire: 2109 * 2110 * Sets the pageability of the specified address 2111 * range in the target map. Regions specified 2112 * as not pageable require locked-down physical 2113 * memory and physical page maps. 2114 * 2115 * The map must not be locked, but a reference 2116 * must remain to the map throughout the call. 2117 * 2118 * This function may be called via the zalloc path and must properly 2119 * reserve map entries for kernel_map. 2120 */ 2121 int 2122 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags) 2123 { 2124 vm_map_entry_t entry; 2125 vm_map_entry_t start_entry; 2126 vm_offset_t end; 2127 int rv = KERN_SUCCESS; 2128 int count; 2129 2130 if (kmflags & KM_KRESERVE) 2131 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT); 2132 else 2133 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2134 vm_map_lock(map); 2135 VM_MAP_RANGE_CHECK(map, start, real_end); 2136 end = real_end; 2137 2138 start_entry = vm_map_clip_range(map, start, end, &count, MAP_CLIP_NO_HOLES); 2139 if (start_entry == NULL) { 2140 vm_map_unlock(map); 2141 rv = KERN_INVALID_ADDRESS; 2142 goto failure; 2143 } 2144 if ((kmflags & KM_PAGEABLE) == 0) { 2145 /* 2146 * Wiring. 2147 * 2148 * 1. Holding the write lock, we create any shadow or zero-fill 2149 * objects that need to be created. Then we clip each map 2150 * entry to the region to be wired and increment its wiring 2151 * count. We create objects before clipping the map entries 2152 * to avoid object proliferation. 2153 * 2154 * 2. We downgrade to a read lock, and call vm_fault_wire to 2155 * fault in the pages for any newly wired area (wired_count is 2156 * 1). 2157 * 2158 * Downgrading to a read lock for vm_fault_wire avoids a 2159 * possible deadlock with another process that may have faulted 2160 * on one of the pages to be wired (it would mark the page busy, 2161 * blocking us, then in turn block on the map lock that we 2162 * hold). Because of problems in the recursive lock package, 2163 * we cannot upgrade to a write lock in vm_map_lookup. Thus, 2164 * any actions that require the write lock must be done 2165 * beforehand. Because we keep the read lock on the map, the 2166 * copy-on-write status of the entries we modify here cannot 2167 * change. 2168 */ 2169 2170 entry = start_entry; 2171 while ((entry != &map->header) && (entry->start < end)) { 2172 /* 2173 * Trivial case if the entry is already wired 2174 */ 2175 if (entry->wired_count) { 2176 entry->wired_count++; 2177 entry = entry->next; 2178 continue; 2179 } 2180 2181 /* 2182 * The entry is being newly wired, we have to setup 2183 * appropriate management structures. A shadow 2184 * object is required for a copy-on-write region, 2185 * or a normal object for a zero-fill region. We 2186 * do not have to do this for entries that point to sub 2187 * maps because we won't hold the lock on the sub map. 2188 */ 2189 if (entry->maptype != VM_MAPTYPE_SUBMAP) { 2190 int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY; 2191 if (copyflag && 2192 ((entry->protection & VM_PROT_WRITE) != 0)) { 2193 vm_map_entry_shadow(entry); 2194 } else if (entry->object.vm_object == NULL && 2195 !map->system_map) { 2196 vm_map_entry_allocate_object(entry); 2197 } 2198 } 2199 2200 entry->wired_count++; 2201 entry = entry->next; 2202 } 2203 2204 /* 2205 * Pass 2. 2206 */ 2207 2208 /* 2209 * HACK HACK HACK HACK 2210 * 2211 * Unlock the map to avoid deadlocks. The in-transit flag 2212 * protects us from most changes but note that 2213 * clipping may still occur. To prevent clipping from 2214 * occuring after the unlock, except for when we are 2215 * blocking in vm_fault_wire, we must run in a critical 2216 * section, otherwise our accesses to entry->start and 2217 * entry->end could be corrupted. We have to enter the 2218 * critical section prior to unlocking so start_entry does 2219 * not change out from under us at the very beginning of the 2220 * loop. 2221 * 2222 * HACK HACK HACK HACK 2223 */ 2224 2225 crit_enter(); 2226 2227 entry = start_entry; 2228 while (entry != &map->header && entry->start < end) { 2229 /* 2230 * If vm_fault_wire fails for any page we need to undo 2231 * what has been done. We decrement the wiring count 2232 * for those pages which have not yet been wired (now) 2233 * and unwire those that have (later). 2234 */ 2235 vm_offset_t save_start = entry->start; 2236 vm_offset_t save_end = entry->end; 2237 2238 if (entry->wired_count == 1) 2239 rv = vm_fault_wire(map, entry, FALSE); 2240 if (rv) { 2241 CLIP_CHECK_BACK(entry, save_start); 2242 for (;;) { 2243 KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly")); 2244 entry->wired_count = 0; 2245 if (entry->end == save_end) 2246 break; 2247 entry = entry->next; 2248 KASSERT(entry != &map->header, ("bad entry clip during backout")); 2249 } 2250 end = save_start; 2251 break; 2252 } 2253 CLIP_CHECK_FWD(entry, save_end); 2254 entry = entry->next; 2255 } 2256 crit_exit(); 2257 2258 /* 2259 * If a failure occured undo everything by falling through 2260 * to the unwiring code. 'end' has already been adjusted 2261 * appropriately. 2262 */ 2263 if (rv) 2264 kmflags |= KM_PAGEABLE; 2265 2266 /* 2267 * start_entry is still IN_TRANSITION but may have been 2268 * clipped since vm_fault_wire() unlocks and relocks the 2269 * map. No matter how clipped it has gotten there should 2270 * be a fragment that is on our start boundary. 2271 */ 2272 CLIP_CHECK_BACK(start_entry, start); 2273 } 2274 2275 if (kmflags & KM_PAGEABLE) { 2276 /* 2277 * This is the unwiring case. We must first ensure that the 2278 * range to be unwired is really wired down. We know there 2279 * are no holes. 2280 */ 2281 entry = start_entry; 2282 while ((entry != &map->header) && (entry->start < end)) { 2283 if (entry->wired_count == 0) { 2284 rv = KERN_INVALID_ARGUMENT; 2285 goto done; 2286 } 2287 entry = entry->next; 2288 } 2289 2290 /* 2291 * Now decrement the wiring count for each region. If a region 2292 * becomes completely unwired, unwire its physical pages and 2293 * mappings. 2294 */ 2295 entry = start_entry; 2296 while ((entry != &map->header) && (entry->start < end)) { 2297 entry->wired_count--; 2298 if (entry->wired_count == 0) 2299 vm_fault_unwire(map, entry); 2300 entry = entry->next; 2301 } 2302 } 2303 done: 2304 vm_map_unclip_range(map, start_entry, start, real_end, &count, 2305 MAP_CLIP_NO_HOLES); 2306 map->timestamp++; 2307 vm_map_unlock(map); 2308 failure: 2309 if (kmflags & KM_KRESERVE) 2310 vm_map_entry_krelease(count); 2311 else 2312 vm_map_entry_release(count); 2313 return (rv); 2314 } 2315 2316 /* 2317 * vm_map_set_wired_quick() 2318 * 2319 * Mark a newly allocated address range as wired but do not fault in 2320 * the pages. The caller is expected to load the pages into the object. 2321 * 2322 * The map must be locked on entry and will remain locked on return. 2323 */ 2324 void 2325 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size, int *countp) 2326 { 2327 vm_map_entry_t scan; 2328 vm_map_entry_t entry; 2329 2330 entry = vm_map_clip_range(map, addr, addr + size, countp, MAP_CLIP_NO_HOLES); 2331 for (scan = entry; scan != &map->header && scan->start < addr + size; scan = scan->next) { 2332 KKASSERT(entry->wired_count == 0); 2333 entry->wired_count = 1; 2334 } 2335 vm_map_unclip_range(map, entry, addr, addr + size, countp, MAP_CLIP_NO_HOLES); 2336 } 2337 2338 /* 2339 * vm_map_clean 2340 * 2341 * Push any dirty cached pages in the address range to their pager. 2342 * If syncio is TRUE, dirty pages are written synchronously. 2343 * If invalidate is TRUE, any cached pages are freed as well. 2344 * 2345 * Returns an error if any part of the specified range is not mapped. 2346 */ 2347 int 2348 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end, boolean_t syncio, 2349 boolean_t invalidate) 2350 { 2351 vm_map_entry_t current; 2352 vm_map_entry_t entry; 2353 vm_size_t size; 2354 vm_object_t object; 2355 vm_ooffset_t offset; 2356 2357 vm_map_lock_read(map); 2358 VM_MAP_RANGE_CHECK(map, start, end); 2359 if (!vm_map_lookup_entry(map, start, &entry)) { 2360 vm_map_unlock_read(map); 2361 return (KERN_INVALID_ADDRESS); 2362 } 2363 /* 2364 * Make a first pass to check for holes. 2365 */ 2366 for (current = entry; current->start < end; current = current->next) { 2367 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2368 vm_map_unlock_read(map); 2369 return (KERN_INVALID_ARGUMENT); 2370 } 2371 if (end > current->end && 2372 (current->next == &map->header || 2373 current->end != current->next->start)) { 2374 vm_map_unlock_read(map); 2375 return (KERN_INVALID_ADDRESS); 2376 } 2377 } 2378 2379 if (invalidate) 2380 pmap_remove(vm_map_pmap(map), start, end); 2381 /* 2382 * Make a second pass, cleaning/uncaching pages from the indicated 2383 * objects as we go. 2384 */ 2385 for (current = entry; current->start < end; current = current->next) { 2386 offset = current->offset + (start - current->start); 2387 size = (end <= current->end ? end : current->end) - start; 2388 if (current->maptype == VM_MAPTYPE_SUBMAP) { 2389 vm_map_t smap; 2390 vm_map_entry_t tentry; 2391 vm_size_t tsize; 2392 2393 smap = current->object.sub_map; 2394 vm_map_lock_read(smap); 2395 vm_map_lookup_entry(smap, offset, &tentry); 2396 tsize = tentry->end - offset; 2397 if (tsize < size) 2398 size = tsize; 2399 object = tentry->object.vm_object; 2400 offset = tentry->offset + (offset - tentry->start); 2401 vm_map_unlock_read(smap); 2402 } else { 2403 object = current->object.vm_object; 2404 } 2405 /* 2406 * Note that there is absolutely no sense in writing out 2407 * anonymous objects, so we track down the vnode object 2408 * to write out. 2409 * We invalidate (remove) all pages from the address space 2410 * anyway, for semantic correctness. 2411 * 2412 * note: certain anonymous maps, such as MAP_NOSYNC maps, 2413 * may start out with a NULL object. 2414 */ 2415 while (object && object->backing_object) { 2416 offset += object->backing_object_offset; 2417 object = object->backing_object; 2418 if (object->size < OFF_TO_IDX( offset + size)) 2419 size = IDX_TO_OFF(object->size) - offset; 2420 } 2421 if (object && (object->type == OBJT_VNODE) && 2422 (current->protection & VM_PROT_WRITE)) { 2423 /* 2424 * Flush pages if writing is allowed, invalidate them 2425 * if invalidation requested. Pages undergoing I/O 2426 * will be ignored by vm_object_page_remove(). 2427 * 2428 * We cannot lock the vnode and then wait for paging 2429 * to complete without deadlocking against vm_fault. 2430 * Instead we simply call vm_object_page_remove() and 2431 * allow it to block internally on a page-by-page 2432 * basis when it encounters pages undergoing async 2433 * I/O. 2434 */ 2435 int flags; 2436 2437 vm_object_reference(object); 2438 vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY); 2439 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 2440 flags |= invalidate ? OBJPC_INVAL : 0; 2441 2442 /* 2443 * When operating on a virtual page table just 2444 * flush the whole object. XXX we probably ought 2445 * to 2446 */ 2447 switch(current->maptype) { 2448 case VM_MAPTYPE_NORMAL: 2449 vm_object_page_clean(object, 2450 OFF_TO_IDX(offset), 2451 OFF_TO_IDX(offset + size + PAGE_MASK), 2452 flags); 2453 break; 2454 case VM_MAPTYPE_VPAGETABLE: 2455 vm_object_page_clean(object, 0, 0, flags); 2456 break; 2457 } 2458 vn_unlock(((struct vnode *)object->handle)); 2459 vm_object_deallocate(object); 2460 } 2461 if (object && invalidate && 2462 ((object->type == OBJT_VNODE) || 2463 (object->type == OBJT_DEVICE))) { 2464 int clean_only = 2465 (object->type == OBJT_DEVICE) ? FALSE : TRUE; 2466 vm_object_reference(object); 2467 switch(current->maptype) { 2468 case VM_MAPTYPE_NORMAL: 2469 vm_object_page_remove(object, 2470 OFF_TO_IDX(offset), 2471 OFF_TO_IDX(offset + size + PAGE_MASK), 2472 clean_only); 2473 break; 2474 case VM_MAPTYPE_VPAGETABLE: 2475 vm_object_page_remove(object, 0, 0, clean_only); 2476 break; 2477 } 2478 vm_object_deallocate(object); 2479 } 2480 start += size; 2481 } 2482 2483 vm_map_unlock_read(map); 2484 return (KERN_SUCCESS); 2485 } 2486 2487 /* 2488 * vm_map_entry_unwire: [ internal use only ] 2489 * 2490 * Make the region specified by this entry pageable. 2491 * 2492 * The map in question should be locked. 2493 * [This is the reason for this routine's existence.] 2494 */ 2495 static void 2496 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) 2497 { 2498 entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2499 entry->wired_count = 0; 2500 vm_fault_unwire(map, entry); 2501 } 2502 2503 /* 2504 * vm_map_entry_delete: [ internal use only ] 2505 * 2506 * Deallocate the given entry from the target map. 2507 */ 2508 static void 2509 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp) 2510 { 2511 vm_map_entry_unlink(map, entry); 2512 map->size -= entry->end - entry->start; 2513 2514 switch(entry->maptype) { 2515 case VM_MAPTYPE_NORMAL: 2516 case VM_MAPTYPE_VPAGETABLE: 2517 vm_object_deallocate(entry->object.vm_object); 2518 break; 2519 default: 2520 break; 2521 } 2522 2523 vm_map_entry_dispose(map, entry, countp); 2524 } 2525 2526 /* 2527 * vm_map_delete: [ internal use only ] 2528 * 2529 * Deallocates the given address range from the target 2530 * map. 2531 */ 2532 int 2533 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp) 2534 { 2535 vm_object_t object; 2536 vm_map_entry_t entry; 2537 vm_map_entry_t first_entry; 2538 2539 again: 2540 /* 2541 * Find the start of the region, and clip it. Set entry to point 2542 * at the first record containing the requested address or, if no 2543 * such record exists, the next record with a greater address. The 2544 * loop will run from this point until a record beyond the termination 2545 * address is encountered. 2546 * 2547 * map->hint must be adjusted to not point to anything we delete, 2548 * so set it to the entry prior to the one being deleted. 2549 * 2550 * GGG see other GGG comment. 2551 */ 2552 if (vm_map_lookup_entry(map, start, &first_entry)) { 2553 entry = first_entry; 2554 vm_map_clip_start(map, entry, start, countp); 2555 map->hint = entry->prev; /* possible problem XXX */ 2556 } else { 2557 map->hint = first_entry; /* possible problem XXX */ 2558 entry = first_entry->next; 2559 } 2560 2561 /* 2562 * If a hole opens up prior to the current first_free then 2563 * adjust first_free. As with map->hint, map->first_free 2564 * cannot be left set to anything we might delete. 2565 */ 2566 if (entry == &map->header) { 2567 map->first_free = &map->header; 2568 } else if (map->first_free->start >= start) { 2569 map->first_free = entry->prev; 2570 } 2571 2572 /* 2573 * Step through all entries in this region 2574 */ 2575 2576 while ((entry != &map->header) && (entry->start < end)) { 2577 vm_map_entry_t next; 2578 vm_offset_t s, e; 2579 vm_pindex_t offidxstart, offidxend, count; 2580 2581 /* 2582 * If we hit an in-transition entry we have to sleep and 2583 * retry. It's easier (and not really slower) to just retry 2584 * since this case occurs so rarely and the hint is already 2585 * pointing at the right place. We have to reset the 2586 * start offset so as not to accidently delete an entry 2587 * another process just created in vacated space. 2588 */ 2589 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { 2590 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; 2591 start = entry->start; 2592 ++mycpu->gd_cnt.v_intrans_coll; 2593 ++mycpu->gd_cnt.v_intrans_wait; 2594 vm_map_transition_wait(map); 2595 goto again; 2596 } 2597 vm_map_clip_end(map, entry, end, countp); 2598 2599 s = entry->start; 2600 e = entry->end; 2601 next = entry->next; 2602 2603 offidxstart = OFF_TO_IDX(entry->offset); 2604 count = OFF_TO_IDX(e - s); 2605 object = entry->object.vm_object; 2606 2607 /* 2608 * Unwire before removing addresses from the pmap; otherwise, 2609 * unwiring will put the entries back in the pmap. 2610 */ 2611 if (entry->wired_count != 0) 2612 vm_map_entry_unwire(map, entry); 2613 2614 offidxend = offidxstart + count; 2615 2616 if (object == &kernel_object) { 2617 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2618 } else { 2619 pmap_remove(map->pmap, s, e); 2620 if (object != NULL && 2621 object->ref_count != 1 && 2622 (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING && 2623 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2624 vm_object_collapse(object); 2625 vm_object_page_remove(object, offidxstart, offidxend, FALSE); 2626 if (object->type == OBJT_SWAP) { 2627 swap_pager_freespace(object, offidxstart, count); 2628 } 2629 if (offidxend >= object->size && 2630 offidxstart < object->size) { 2631 object->size = offidxstart; 2632 } 2633 } 2634 } 2635 2636 /* 2637 * Delete the entry (which may delete the object) only after 2638 * removing all pmap entries pointing to its pages. 2639 * (Otherwise, its page frames may be reallocated, and any 2640 * modify bits will be set in the wrong object!) 2641 */ 2642 vm_map_entry_delete(map, entry, countp); 2643 entry = next; 2644 } 2645 return (KERN_SUCCESS); 2646 } 2647 2648 /* 2649 * vm_map_remove: 2650 * 2651 * Remove the given address range from the target map. 2652 * This is the exported form of vm_map_delete. 2653 */ 2654 int 2655 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) 2656 { 2657 int result; 2658 int count; 2659 2660 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 2661 vm_map_lock(map); 2662 VM_MAP_RANGE_CHECK(map, start, end); 2663 result = vm_map_delete(map, start, end, &count); 2664 vm_map_unlock(map); 2665 vm_map_entry_release(count); 2666 2667 return (result); 2668 } 2669 2670 /* 2671 * vm_map_check_protection: 2672 * 2673 * Assert that the target map allows the specified 2674 * privilege on the entire address region given. 2675 * The entire region must be allocated. 2676 */ 2677 boolean_t 2678 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, 2679 vm_prot_t protection) 2680 { 2681 vm_map_entry_t entry; 2682 vm_map_entry_t tmp_entry; 2683 2684 if (!vm_map_lookup_entry(map, start, &tmp_entry)) { 2685 return (FALSE); 2686 } 2687 entry = tmp_entry; 2688 2689 while (start < end) { 2690 if (entry == &map->header) { 2691 return (FALSE); 2692 } 2693 /* 2694 * No holes allowed! 2695 */ 2696 2697 if (start < entry->start) { 2698 return (FALSE); 2699 } 2700 /* 2701 * Check protection associated with entry. 2702 */ 2703 2704 if ((entry->protection & protection) != protection) { 2705 return (FALSE); 2706 } 2707 /* go to next entry */ 2708 2709 start = entry->end; 2710 entry = entry->next; 2711 } 2712 return (TRUE); 2713 } 2714 2715 /* 2716 * Split the pages in a map entry into a new object. This affords 2717 * easier removal of unused pages, and keeps object inheritance from 2718 * being a negative impact on memory usage. 2719 */ 2720 static void 2721 vm_map_split(vm_map_entry_t entry) 2722 { 2723 vm_page_t m; 2724 vm_object_t orig_object, new_object, source; 2725 vm_offset_t s, e; 2726 vm_pindex_t offidxstart, offidxend, idx; 2727 vm_size_t size; 2728 vm_ooffset_t offset; 2729 2730 orig_object = entry->object.vm_object; 2731 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 2732 return; 2733 if (orig_object->ref_count <= 1) 2734 return; 2735 2736 offset = entry->offset; 2737 s = entry->start; 2738 e = entry->end; 2739 2740 offidxstart = OFF_TO_IDX(offset); 2741 offidxend = offidxstart + OFF_TO_IDX(e - s); 2742 size = offidxend - offidxstart; 2743 2744 new_object = vm_pager_allocate(orig_object->type, NULL, 2745 IDX_TO_OFF(size), VM_PROT_ALL, 0); 2746 if (new_object == NULL) 2747 return; 2748 2749 source = orig_object->backing_object; 2750 if (source != NULL) { 2751 vm_object_reference(source); /* Referenced by new_object */ 2752 LIST_INSERT_HEAD(&source->shadow_head, 2753 new_object, shadow_list); 2754 vm_object_clear_flag(source, OBJ_ONEMAPPING); 2755 new_object->backing_object_offset = 2756 orig_object->backing_object_offset + IDX_TO_OFF(offidxstart); 2757 new_object->backing_object = source; 2758 source->shadow_count++; 2759 source->generation++; 2760 } 2761 2762 for (idx = 0; idx < size; idx++) { 2763 vm_page_t m; 2764 2765 /* 2766 * A critical section is required to avoid a race between 2767 * the lookup and an interrupt/unbusy/free and our busy 2768 * check. 2769 */ 2770 crit_enter(); 2771 retry: 2772 m = vm_page_lookup(orig_object, offidxstart + idx); 2773 if (m == NULL) { 2774 crit_exit(); 2775 continue; 2776 } 2777 2778 /* 2779 * We must wait for pending I/O to complete before we can 2780 * rename the page. 2781 * 2782 * We do not have to VM_PROT_NONE the page as mappings should 2783 * not be changed by this operation. 2784 */ 2785 if (vm_page_sleep_busy(m, TRUE, "spltwt")) 2786 goto retry; 2787 vm_page_busy(m); 2788 vm_page_rename(m, new_object, idx); 2789 /* page automatically made dirty by rename and cache handled */ 2790 vm_page_busy(m); 2791 crit_exit(); 2792 } 2793 2794 if (orig_object->type == OBJT_SWAP) { 2795 vm_object_pip_add(orig_object, 1); 2796 /* 2797 * copy orig_object pages into new_object 2798 * and destroy unneeded pages in 2799 * shadow object. 2800 */ 2801 swap_pager_copy(orig_object, new_object, offidxstart, 0); 2802 vm_object_pip_wakeup(orig_object); 2803 } 2804 2805 /* 2806 * Wakeup the pages we played with. No spl protection is needed 2807 * for a simple wakeup. 2808 */ 2809 for (idx = 0; idx < size; idx++) { 2810 m = vm_page_lookup(new_object, idx); 2811 if (m) 2812 vm_page_wakeup(m); 2813 } 2814 2815 entry->object.vm_object = new_object; 2816 entry->offset = 0LL; 2817 vm_object_deallocate(orig_object); 2818 } 2819 2820 /* 2821 * vm_map_copy_entry: 2822 * 2823 * Copies the contents of the source entry to the destination 2824 * entry. The entries *must* be aligned properly. 2825 */ 2826 static void 2827 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map, 2828 vm_map_entry_t src_entry, vm_map_entry_t dst_entry) 2829 { 2830 vm_object_t src_object; 2831 2832 if (dst_entry->maptype == VM_MAPTYPE_SUBMAP) 2833 return; 2834 if (src_entry->maptype == VM_MAPTYPE_SUBMAP) 2835 return; 2836 2837 if (src_entry->wired_count == 0) { 2838 /* 2839 * If the source entry is marked needs_copy, it is already 2840 * write-protected. 2841 */ 2842 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { 2843 pmap_protect(src_map->pmap, 2844 src_entry->start, 2845 src_entry->end, 2846 src_entry->protection & ~VM_PROT_WRITE); 2847 } 2848 2849 /* 2850 * Make a copy of the object. 2851 */ 2852 if ((src_object = src_entry->object.vm_object) != NULL) { 2853 if ((src_object->handle == NULL) && 2854 (src_object->type == OBJT_DEFAULT || 2855 src_object->type == OBJT_SWAP)) { 2856 vm_object_collapse(src_object); 2857 if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) { 2858 vm_map_split(src_entry); 2859 src_object = src_entry->object.vm_object; 2860 } 2861 } 2862 2863 vm_object_reference(src_object); 2864 vm_object_clear_flag(src_object, OBJ_ONEMAPPING); 2865 dst_entry->object.vm_object = src_object; 2866 src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2867 dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY); 2868 dst_entry->offset = src_entry->offset; 2869 } else { 2870 dst_entry->object.vm_object = NULL; 2871 dst_entry->offset = 0; 2872 } 2873 2874 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, 2875 dst_entry->end - dst_entry->start, src_entry->start); 2876 } else { 2877 /* 2878 * Of course, wired down pages can't be set copy-on-write. 2879 * Cause wired pages to be copied into the new map by 2880 * simulating faults (the new pages are pageable) 2881 */ 2882 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); 2883 } 2884 } 2885 2886 /* 2887 * vmspace_fork: 2888 * Create a new process vmspace structure and vm_map 2889 * based on those of an existing process. The new map 2890 * is based on the old map, according to the inheritance 2891 * values on the regions in that map. 2892 * 2893 * The source map must not be locked. 2894 */ 2895 struct vmspace * 2896 vmspace_fork(struct vmspace *vm1) 2897 { 2898 struct vmspace *vm2; 2899 vm_map_t old_map = &vm1->vm_map; 2900 vm_map_t new_map; 2901 vm_map_entry_t old_entry; 2902 vm_map_entry_t new_entry; 2903 vm_object_t object; 2904 int count; 2905 2906 vm_map_lock(old_map); 2907 old_map->infork = 1; 2908 2909 /* 2910 * XXX Note: upcalls are not copied. 2911 */ 2912 vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); 2913 bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, 2914 (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); 2915 new_map = &vm2->vm_map; /* XXX */ 2916 new_map->timestamp = 1; 2917 2918 count = 0; 2919 old_entry = old_map->header.next; 2920 while (old_entry != &old_map->header) { 2921 ++count; 2922 old_entry = old_entry->next; 2923 } 2924 2925 count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); 2926 2927 old_entry = old_map->header.next; 2928 while (old_entry != &old_map->header) { 2929 if (old_entry->maptype == VM_MAPTYPE_SUBMAP) 2930 panic("vm_map_fork: encountered a submap"); 2931 2932 switch (old_entry->inheritance) { 2933 case VM_INHERIT_NONE: 2934 break; 2935 2936 case VM_INHERIT_SHARE: 2937 /* 2938 * Clone the entry, creating the shared object if 2939 * necessary. 2940 */ 2941 object = old_entry->object.vm_object; 2942 if (object == NULL) { 2943 vm_map_entry_allocate_object(old_entry); 2944 object = old_entry->object.vm_object; 2945 } 2946 2947 /* 2948 * Add the reference before calling vm_map_entry_shadow 2949 * to insure that a shadow object is created. 2950 */ 2951 vm_object_reference(object); 2952 if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { 2953 vm_map_entry_shadow(old_entry); 2954 /* Transfer the second reference too. */ 2955 vm_object_reference( 2956 old_entry->object.vm_object); 2957 vm_object_deallocate(object); 2958 object = old_entry->object.vm_object; 2959 } 2960 vm_object_clear_flag(object, OBJ_ONEMAPPING); 2961 2962 /* 2963 * Clone the entry, referencing the shared object. 2964 */ 2965 new_entry = vm_map_entry_create(new_map, &count); 2966 *new_entry = *old_entry; 2967 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2968 new_entry->wired_count = 0; 2969 2970 /* 2971 * Insert the entry into the new map -- we know we're 2972 * inserting at the end of the new map. 2973 */ 2974 2975 vm_map_entry_link(new_map, new_map->header.prev, 2976 new_entry); 2977 2978 /* 2979 * Update the physical map 2980 */ 2981 2982 pmap_copy(new_map->pmap, old_map->pmap, 2983 new_entry->start, 2984 (old_entry->end - old_entry->start), 2985 old_entry->start); 2986 break; 2987 2988 case VM_INHERIT_COPY: 2989 /* 2990 * Clone the entry and link into the map. 2991 */ 2992 new_entry = vm_map_entry_create(new_map, &count); 2993 *new_entry = *old_entry; 2994 new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; 2995 new_entry->wired_count = 0; 2996 new_entry->object.vm_object = NULL; 2997 vm_map_entry_link(new_map, new_map->header.prev, 2998 new_entry); 2999 vm_map_copy_entry(old_map, new_map, old_entry, 3000 new_entry); 3001 break; 3002 } 3003 old_entry = old_entry->next; 3004 } 3005 3006 new_map->size = old_map->size; 3007 old_map->infork = 0; 3008 vm_map_unlock(old_map); 3009 vm_map_entry_release(count); 3010 3011 return (vm2); 3012 } 3013 3014 int 3015 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, 3016 int flags, vm_prot_t prot, vm_prot_t max, int cow) 3017 { 3018 vm_map_entry_t prev_entry; 3019 vm_map_entry_t new_stack_entry; 3020 vm_size_t init_ssize; 3021 int rv; 3022 int count; 3023 vm_offset_t tmpaddr; 3024 3025 cow |= MAP_IS_STACK; 3026 3027 if (max_ssize < sgrowsiz) 3028 init_ssize = max_ssize; 3029 else 3030 init_ssize = sgrowsiz; 3031 3032 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3033 vm_map_lock(map); 3034 3035 /* 3036 * Find space for the mapping 3037 */ 3038 if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) { 3039 if (vm_map_findspace(map, addrbos, max_ssize, 1, 3040 flags, &tmpaddr)) { 3041 vm_map_unlock(map); 3042 vm_map_entry_release(count); 3043 return (KERN_NO_SPACE); 3044 } 3045 addrbos = tmpaddr; 3046 } 3047 3048 /* If addr is already mapped, no go */ 3049 if (vm_map_lookup_entry(map, addrbos, &prev_entry)) { 3050 vm_map_unlock(map); 3051 vm_map_entry_release(count); 3052 return (KERN_NO_SPACE); 3053 } 3054 3055 #if 0 3056 /* XXX already handled by kern_mmap() */ 3057 /* If we would blow our VMEM resource limit, no go */ 3058 if (map->size + init_ssize > 3059 curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3060 vm_map_unlock(map); 3061 vm_map_entry_release(count); 3062 return (KERN_NO_SPACE); 3063 } 3064 #endif 3065 3066 /* 3067 * If we can't accomodate max_ssize in the current mapping, 3068 * no go. However, we need to be aware that subsequent user 3069 * mappings might map into the space we have reserved for 3070 * stack, and currently this space is not protected. 3071 * 3072 * Hopefully we will at least detect this condition 3073 * when we try to grow the stack. 3074 */ 3075 if ((prev_entry->next != &map->header) && 3076 (prev_entry->next->start < addrbos + max_ssize)) { 3077 vm_map_unlock(map); 3078 vm_map_entry_release(count); 3079 return (KERN_NO_SPACE); 3080 } 3081 3082 /* 3083 * We initially map a stack of only init_ssize. We will 3084 * grow as needed later. Since this is to be a grow 3085 * down stack, we map at the top of the range. 3086 * 3087 * Note: we would normally expect prot and max to be 3088 * VM_PROT_ALL, and cow to be 0. Possibly we should 3089 * eliminate these as input parameters, and just 3090 * pass these values here in the insert call. 3091 */ 3092 rv = vm_map_insert(map, &count, 3093 NULL, 0, addrbos + max_ssize - init_ssize, 3094 addrbos + max_ssize, 3095 VM_MAPTYPE_NORMAL, 3096 prot, max, 3097 cow); 3098 3099 /* Now set the avail_ssize amount */ 3100 if (rv == KERN_SUCCESS) { 3101 if (prev_entry != &map->header) 3102 vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count); 3103 new_stack_entry = prev_entry->next; 3104 if (new_stack_entry->end != addrbos + max_ssize || 3105 new_stack_entry->start != addrbos + max_ssize - init_ssize) 3106 panic ("Bad entry start/end for new stack entry"); 3107 else 3108 new_stack_entry->aux.avail_ssize = max_ssize - init_ssize; 3109 } 3110 3111 vm_map_unlock(map); 3112 vm_map_entry_release(count); 3113 return (rv); 3114 } 3115 3116 /* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the 3117 * desired address is already mapped, or if we successfully grow 3118 * the stack. Also returns KERN_SUCCESS if addr is outside the 3119 * stack range (this is strange, but preserves compatibility with 3120 * the grow function in vm_machdep.c). 3121 */ 3122 int 3123 vm_map_growstack (struct proc *p, vm_offset_t addr) 3124 { 3125 vm_map_entry_t prev_entry; 3126 vm_map_entry_t stack_entry; 3127 vm_map_entry_t new_stack_entry; 3128 struct vmspace *vm = p->p_vmspace; 3129 vm_map_t map = &vm->vm_map; 3130 vm_offset_t end; 3131 int grow_amount; 3132 int rv = KERN_SUCCESS; 3133 int is_procstack; 3134 int use_read_lock = 1; 3135 int count; 3136 3137 count = vm_map_entry_reserve(MAP_RESERVE_COUNT); 3138 Retry: 3139 if (use_read_lock) 3140 vm_map_lock_read(map); 3141 else 3142 vm_map_lock(map); 3143 3144 /* If addr is already in the entry range, no need to grow.*/ 3145 if (vm_map_lookup_entry(map, addr, &prev_entry)) 3146 goto done; 3147 3148 if ((stack_entry = prev_entry->next) == &map->header) 3149 goto done; 3150 if (prev_entry == &map->header) 3151 end = stack_entry->start - stack_entry->aux.avail_ssize; 3152 else 3153 end = prev_entry->end; 3154 3155 /* 3156 * This next test mimics the old grow function in vm_machdep.c. 3157 * It really doesn't quite make sense, but we do it anyway 3158 * for compatibility. 3159 * 3160 * If not growable stack, return success. This signals the 3161 * caller to proceed as he would normally with normal vm. 3162 */ 3163 if (stack_entry->aux.avail_ssize < 1 || 3164 addr >= stack_entry->start || 3165 addr < stack_entry->start - stack_entry->aux.avail_ssize) { 3166 goto done; 3167 } 3168 3169 /* Find the minimum grow amount */ 3170 grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE); 3171 if (grow_amount > stack_entry->aux.avail_ssize) { 3172 rv = KERN_NO_SPACE; 3173 goto done; 3174 } 3175 3176 /* 3177 * If there is no longer enough space between the entries 3178 * nogo, and adjust the available space. Note: this 3179 * should only happen if the user has mapped into the 3180 * stack area after the stack was created, and is 3181 * probably an error. 3182 * 3183 * This also effectively destroys any guard page the user 3184 * might have intended by limiting the stack size. 3185 */ 3186 if (grow_amount > stack_entry->start - end) { 3187 if (use_read_lock && vm_map_lock_upgrade(map)) { 3188 use_read_lock = 0; 3189 goto Retry; 3190 } 3191 use_read_lock = 0; 3192 stack_entry->aux.avail_ssize = stack_entry->start - end; 3193 rv = KERN_NO_SPACE; 3194 goto done; 3195 } 3196 3197 is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; 3198 3199 /* If this is the main process stack, see if we're over the 3200 * stack limit. 3201 */ 3202 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3203 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3204 rv = KERN_NO_SPACE; 3205 goto done; 3206 } 3207 3208 /* Round up the grow amount modulo SGROWSIZ */ 3209 grow_amount = roundup (grow_amount, sgrowsiz); 3210 if (grow_amount > stack_entry->aux.avail_ssize) { 3211 grow_amount = stack_entry->aux.avail_ssize; 3212 } 3213 if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > 3214 p->p_rlimit[RLIMIT_STACK].rlim_cur)) { 3215 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - 3216 ctob(vm->vm_ssize); 3217 } 3218 3219 /* If we would blow our VMEM resource limit, no go */ 3220 if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 3221 rv = KERN_NO_SPACE; 3222 goto done; 3223 } 3224 3225 if (use_read_lock && vm_map_lock_upgrade(map)) { 3226 use_read_lock = 0; 3227 goto Retry; 3228 } 3229 use_read_lock = 0; 3230 3231 /* Get the preliminary new entry start value */ 3232 addr = stack_entry->start - grow_amount; 3233 3234 /* If this puts us into the previous entry, cut back our growth 3235 * to the available space. Also, see the note above. 3236 */ 3237 if (addr < end) { 3238 stack_entry->aux.avail_ssize = stack_entry->start - end; 3239 addr = end; 3240 } 3241 3242 rv = vm_map_insert(map, &count, 3243 NULL, 0, addr, stack_entry->start, 3244 VM_MAPTYPE_NORMAL, 3245 VM_PROT_ALL, VM_PROT_ALL, 3246 0); 3247 3248 /* Adjust the available stack space by the amount we grew. */ 3249 if (rv == KERN_SUCCESS) { 3250 if (prev_entry != &map->header) 3251 vm_map_clip_end(map, prev_entry, addr, &count); 3252 new_stack_entry = prev_entry->next; 3253 if (new_stack_entry->end != stack_entry->start || 3254 new_stack_entry->start != addr) 3255 panic ("Bad stack grow start/end in new stack entry"); 3256 else { 3257 new_stack_entry->aux.avail_ssize = 3258 stack_entry->aux.avail_ssize - 3259 (new_stack_entry->end - new_stack_entry->start); 3260 if (is_procstack) 3261 vm->vm_ssize += btoc(new_stack_entry->end - 3262 new_stack_entry->start); 3263 } 3264 } 3265 3266 done: 3267 if (use_read_lock) 3268 vm_map_unlock_read(map); 3269 else 3270 vm_map_unlock(map); 3271 vm_map_entry_release(count); 3272 return (rv); 3273 } 3274 3275 /* 3276 * Unshare the specified VM space for exec. If other processes are 3277 * mapped to it, then create a new one. The new vmspace is null. 3278 */ 3279 void 3280 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 3281 { 3282 struct vmspace *oldvmspace = p->p_vmspace; 3283 struct vmspace *newvmspace; 3284 vm_map_t map = &p->p_vmspace->vm_map; 3285 3286 /* 3287 * If we are execing a resident vmspace we fork it, otherwise 3288 * we create a new vmspace. Note that exitingcnt and upcalls 3289 * are not copied to the new vmspace. 3290 */ 3291 if (vmcopy) { 3292 newvmspace = vmspace_fork(vmcopy); 3293 } else { 3294 newvmspace = vmspace_alloc(map->min_offset, map->max_offset); 3295 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, 3296 (caddr_t)&oldvmspace->vm_endcopy - 3297 (caddr_t)&oldvmspace->vm_startcopy); 3298 } 3299 3300 /* 3301 * Finish initializing the vmspace before assigning it 3302 * to the process. The vmspace will become the current vmspace 3303 * if p == curproc. 3304 */ 3305 pmap_pinit2(vmspace_pmap(newvmspace)); 3306 pmap_replacevm(p, newvmspace, 0); 3307 sysref_put(&oldvmspace->vm_sysref); 3308 } 3309 3310 /* 3311 * Unshare the specified VM space for forcing COW. This 3312 * is called by rfork, for the (RFMEM|RFPROC) == 0 case. 3313 * 3314 * The exitingcnt test is not strictly necessary but has been 3315 * included for code sanity (to make the code a bit more deterministic). 3316 */ 3317 3318 void 3319 vmspace_unshare(struct proc *p) 3320 { 3321 struct vmspace *oldvmspace = p->p_vmspace; 3322 struct vmspace *newvmspace; 3323 3324 if (oldvmspace->vm_sysref.refcnt == 1 && oldvmspace->vm_exitingcnt == 0) 3325 return; 3326 newvmspace = vmspace_fork(oldvmspace); 3327 pmap_pinit2(vmspace_pmap(newvmspace)); 3328 pmap_replacevm(p, newvmspace, 0); 3329 sysref_put(&oldvmspace->vm_sysref); 3330 } 3331 3332 /* 3333 * vm_map_lookup: 3334 * 3335 * Finds the VM object, offset, and 3336 * protection for a given virtual address in the 3337 * specified map, assuming a page fault of the 3338 * type specified. 3339 * 3340 * Leaves the map in question locked for read; return 3341 * values are guaranteed until a vm_map_lookup_done 3342 * call is performed. Note that the map argument 3343 * is in/out; the returned map must be used in 3344 * the call to vm_map_lookup_done. 3345 * 3346 * A handle (out_entry) is returned for use in 3347 * vm_map_lookup_done, to make that fast. 3348 * 3349 * If a lookup is requested with "write protection" 3350 * specified, the map may be changed to perform virtual 3351 * copying operations, although the data referenced will 3352 * remain the same. 3353 */ 3354 int 3355 vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ 3356 vm_offset_t vaddr, 3357 vm_prot_t fault_typea, 3358 vm_map_entry_t *out_entry, /* OUT */ 3359 vm_object_t *object, /* OUT */ 3360 vm_pindex_t *pindex, /* OUT */ 3361 vm_prot_t *out_prot, /* OUT */ 3362 boolean_t *wired) /* OUT */ 3363 { 3364 vm_map_entry_t entry; 3365 vm_map_t map = *var_map; 3366 vm_prot_t prot; 3367 vm_prot_t fault_type = fault_typea; 3368 int use_read_lock = 1; 3369 int rv = KERN_SUCCESS; 3370 3371 RetryLookup: 3372 if (use_read_lock) 3373 vm_map_lock_read(map); 3374 else 3375 vm_map_lock(map); 3376 3377 /* 3378 * If the map has an interesting hint, try it before calling full 3379 * blown lookup routine. 3380 */ 3381 entry = map->hint; 3382 *out_entry = entry; 3383 3384 if ((entry == &map->header) || 3385 (vaddr < entry->start) || (vaddr >= entry->end)) { 3386 vm_map_entry_t tmp_entry; 3387 3388 /* 3389 * Entry was either not a valid hint, or the vaddr was not 3390 * contained in the entry, so do a full lookup. 3391 */ 3392 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { 3393 rv = KERN_INVALID_ADDRESS; 3394 goto done; 3395 } 3396 3397 entry = tmp_entry; 3398 *out_entry = entry; 3399 } 3400 3401 /* 3402 * Handle submaps. 3403 */ 3404 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3405 vm_map_t old_map = map; 3406 3407 *var_map = map = entry->object.sub_map; 3408 if (use_read_lock) 3409 vm_map_unlock_read(old_map); 3410 else 3411 vm_map_unlock(old_map); 3412 use_read_lock = 1; 3413 goto RetryLookup; 3414 } 3415 3416 /* 3417 * Check whether this task is allowed to have this page. 3418 * Note the special case for MAP_ENTRY_COW 3419 * pages with an override. This is to implement a forced 3420 * COW for debuggers. 3421 */ 3422 3423 if (fault_type & VM_PROT_OVERRIDE_WRITE) 3424 prot = entry->max_protection; 3425 else 3426 prot = entry->protection; 3427 3428 fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 3429 if ((fault_type & prot) != fault_type) { 3430 rv = KERN_PROTECTION_FAILURE; 3431 goto done; 3432 } 3433 3434 if ((entry->eflags & MAP_ENTRY_USER_WIRED) && 3435 (entry->eflags & MAP_ENTRY_COW) && 3436 (fault_type & VM_PROT_WRITE) && 3437 (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { 3438 rv = KERN_PROTECTION_FAILURE; 3439 goto done; 3440 } 3441 3442 /* 3443 * If this page is not pageable, we have to get it for all possible 3444 * accesses. 3445 */ 3446 *wired = (entry->wired_count != 0); 3447 if (*wired) 3448 prot = fault_type = entry->protection; 3449 3450 /* 3451 * Virtual page tables may need to update the accessed (A) bit 3452 * in a page table entry. Upgrade the fault to a write fault for 3453 * that case if the map will support it. If the map does not support 3454 * it the page table entry simply will not be updated. 3455 */ 3456 if (entry->maptype == VM_MAPTYPE_VPAGETABLE) { 3457 if (prot & VM_PROT_WRITE) 3458 fault_type |= VM_PROT_WRITE; 3459 } 3460 3461 /* 3462 * If the entry was copy-on-write, we either ... 3463 */ 3464 if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { 3465 /* 3466 * If we want to write the page, we may as well handle that 3467 * now since we've got the map locked. 3468 * 3469 * If we don't need to write the page, we just demote the 3470 * permissions allowed. 3471 */ 3472 3473 if (fault_type & VM_PROT_WRITE) { 3474 /* 3475 * Make a new object, and place it in the object 3476 * chain. Note that no new references have appeared 3477 * -- one just moved from the map to the new 3478 * object. 3479 */ 3480 3481 if (use_read_lock && vm_map_lock_upgrade(map)) { 3482 use_read_lock = 0; 3483 goto RetryLookup; 3484 } 3485 use_read_lock = 0; 3486 3487 vm_map_entry_shadow(entry); 3488 } else { 3489 /* 3490 * We're attempting to read a copy-on-write page -- 3491 * don't allow writes. 3492 */ 3493 3494 prot &= ~VM_PROT_WRITE; 3495 } 3496 } 3497 3498 /* 3499 * Create an object if necessary. 3500 */ 3501 if (entry->object.vm_object == NULL && 3502 !map->system_map) { 3503 if (use_read_lock && vm_map_lock_upgrade(map)) { 3504 use_read_lock = 0; 3505 goto RetryLookup; 3506 } 3507 use_read_lock = 0; 3508 vm_map_entry_allocate_object(entry); 3509 } 3510 3511 /* 3512 * Return the object/offset from this entry. If the entry was 3513 * copy-on-write or empty, it has been fixed up. 3514 */ 3515 3516 *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset); 3517 *object = entry->object.vm_object; 3518 3519 /* 3520 * Return whether this is the only map sharing this data. On 3521 * success we return with a read lock held on the map. On failure 3522 * we return with the map unlocked. 3523 */ 3524 *out_prot = prot; 3525 done: 3526 if (rv == KERN_SUCCESS) { 3527 if (use_read_lock == 0) 3528 vm_map_lock_downgrade(map); 3529 } else if (use_read_lock) { 3530 vm_map_unlock_read(map); 3531 } else { 3532 vm_map_unlock(map); 3533 } 3534 return (rv); 3535 } 3536 3537 /* 3538 * vm_map_lookup_done: 3539 * 3540 * Releases locks acquired by a vm_map_lookup 3541 * (according to the handle returned by that lookup). 3542 */ 3543 3544 void 3545 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) 3546 { 3547 /* 3548 * Unlock the main-level map 3549 */ 3550 vm_map_unlock_read(map); 3551 if (count) 3552 vm_map_entry_release(count); 3553 } 3554 3555 #include "opt_ddb.h" 3556 #ifdef DDB 3557 #include <sys/kernel.h> 3558 3559 #include <ddb/ddb.h> 3560 3561 /* 3562 * vm_map_print: [ debug ] 3563 */ 3564 DB_SHOW_COMMAND(map, vm_map_print) 3565 { 3566 static int nlines; 3567 /* XXX convert args. */ 3568 vm_map_t map = (vm_map_t)addr; 3569 boolean_t full = have_addr; 3570 3571 vm_map_entry_t entry; 3572 3573 db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", 3574 (void *)map, 3575 (void *)map->pmap, map->nentries, map->timestamp); 3576 nlines++; 3577 3578 if (!full && db_indent) 3579 return; 3580 3581 db_indent += 2; 3582 for (entry = map->header.next; entry != &map->header; 3583 entry = entry->next) { 3584 db_iprintf("map entry %p: start=%p, end=%p\n", 3585 (void *)entry, (void *)entry->start, (void *)entry->end); 3586 nlines++; 3587 { 3588 static char *inheritance_name[4] = 3589 {"share", "copy", "none", "donate_copy"}; 3590 3591 db_iprintf(" prot=%x/%x/%s", 3592 entry->protection, 3593 entry->max_protection, 3594 inheritance_name[(int)(unsigned char)entry->inheritance]); 3595 if (entry->wired_count != 0) 3596 db_printf(", wired"); 3597 } 3598 if (entry->maptype == VM_MAPTYPE_SUBMAP) { 3599 /* XXX no %qd in kernel. Truncate entry->offset. */ 3600 db_printf(", share=%p, offset=0x%lx\n", 3601 (void *)entry->object.sub_map, 3602 (long)entry->offset); 3603 nlines++; 3604 if ((entry->prev == &map->header) || 3605 (entry->prev->object.sub_map != 3606 entry->object.sub_map)) { 3607 db_indent += 2; 3608 vm_map_print((db_expr_t)(intptr_t) 3609 entry->object.sub_map, 3610 full, 0, NULL); 3611 db_indent -= 2; 3612 } 3613 } else { 3614 /* XXX no %qd in kernel. Truncate entry->offset. */ 3615 db_printf(", object=%p, offset=0x%lx", 3616 (void *)entry->object.vm_object, 3617 (long)entry->offset); 3618 if (entry->eflags & MAP_ENTRY_COW) 3619 db_printf(", copy (%s)", 3620 (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); 3621 db_printf("\n"); 3622 nlines++; 3623 3624 if ((entry->prev == &map->header) || 3625 (entry->prev->object.vm_object != 3626 entry->object.vm_object)) { 3627 db_indent += 2; 3628 vm_object_print((db_expr_t)(intptr_t) 3629 entry->object.vm_object, 3630 full, 0, NULL); 3631 nlines += 4; 3632 db_indent -= 2; 3633 } 3634 } 3635 } 3636 db_indent -= 2; 3637 if (db_indent == 0) 3638 nlines = 0; 3639 } 3640 3641 3642 DB_SHOW_COMMAND(procvm, procvm) 3643 { 3644 struct proc *p; 3645 3646 if (have_addr) { 3647 p = (struct proc *) addr; 3648 } else { 3649 p = curproc; 3650 } 3651 3652 db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", 3653 (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, 3654 (void *)vmspace_pmap(p->p_vmspace)); 3655 3656 vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); 3657 } 3658 3659 #endif /* DDB */ 3660